Tag Archives: Tokyo Institute of Technology

Microsoft, D-Wave Systems, quantum computing, and quantum supremacy?

Before diving into some of the latest quantum computing doings, here’s why quantum computing is so highly prized and chased after, from the Quantum supremacy Wikipedia entry, Note: Links have been removed,

In quantum computing, quantum supremacy or quantum advantage is the goal of demonstrating that a programmable quantum computer can solve a problem that no classical computer can solve in any feasible amount of time, irrespective of the usefulness of the problem.[1][2][3] The term was coined by John Preskill in 2011,[1][4] but the concept dates to Yuri Manin’s 1980[5] and Richard Feynman’s 1981[6] proposals of quantum computing.

Quantum supremacy and quantum advantage have been mentioned a few times here over the years. You can check my March 6, 2020 posting for when researchers from the University of California at Santa Barbara claimed quantum supremacy and my July 31, 2023 posting for when D-Wave Systems claimed a quantum advantage on optimization problems. I’d understood quantum supremacy and quantum advantage to be synonymous but according the article in Betakit (keep scrolling down to the D-Wave subhead and then, to ‘A controversy of sorts’ subhead in this posting), that’s not so.

The latest news on the quantum front comes from Microsoft (February 2025) and D-Wave systems (March 2025).

Microsoft claims a new state of matter for breakthroughs in quantum computing

Here’s the February 19, 2025 news announcement from Microsoft’s Chetan Nayak, Technical Fellow and Corporate Vice President of Quantum Hardware, Note: Links have been removed,

Quantum computers promise to transform science and society—but only after they achieve the scale that once seemed distant and elusive, and their reliability is ensured by quantum error correction. Today, we’re announcing rapid advancements on the path to useful quantum computing:

  • Majorana 1: the world’s first Quantum Processing Unit (QPU) powered by a Topological Core, designed to scale to a million qubits on a single chip.
  • A hardware-protected topological qubit: research published today in Nature, along with data shared at the Station Q meeting, demonstrate our ability to harness a new type of material and engineer a radically different type of qubit that is small, fast, and digitally controlled.
  • A device roadmap to reliable quantum computation: our path from single-qubit devices to arrays that enable quantum error correction.
  • Building the world’s first fault-tolerant prototype (FTP) based on topological qubits: Microsoft is on track to build an FTP of a scalable quantum computer—in years, not decades—as part of the final phase of the Defense Advanced Research Projects Agency (DARPA) Underexplored Systems for Utility-Scale Quantum Computing (US2QC) program.

Together, these milestones mark a pivotal moment in quantum computing as we advance from scientific exploration to technological innovation.

Harnessing a new type of material

All of today’s announcements build on our team’s recent breakthrough: the world’s first topoconductor. This revolutionary class of materials enables us to create topological superconductivity, a new state of matter that previously existed only in theory. The advance stems from Microsoft’s innovations in the design and fabrication of gate-defined devices that combine indium arsenide (a semiconductor) and aluminum (a superconductor). When cooled to near absolute zero and tuned with magnetic fields, these devices form topological superconducting nanowires with Majorana Zero Modes (MZMs) at the wires’ ends.

Chris Vallance’s February 19, 2025 article for the British Broadcasting Corporation (BBC) news online website provides a description of Microsoft’s claims and makes note of the competitive quantum research environment,

Microsoft has unveiled a new chip called Majorana 1 that it says will enable the creation of quantum computers able to solve “meaningful, industrial-scale problems in years, not decades”.

It is the latest development in quantum computing – tech which uses principles of particle physics to create a new type of computer able to solve problems ordinary computers cannot.

Creating quantum computers powerful enough to solve important real-world problems is very challenging – and some experts believe them to be decades away.

Microsoft says this timetable can now be sped up because of the “transformative” progress it has made in developing the new chip involving a “topological conductor”, based on a new material it has produced.

The firm believes its topoconductor has the potential to be as revolutionary as the semiconductor was in the history of computing.

But experts have told the BBC more data is needed before the significance of the new research – and its effect on quantum computing – can be fully assessed.

Jensen Huang – boss of the leading chip firm, Nvidia – said in January he believed “very useful” quantum computing would come in 20 years.

Chetan Nayak, a technical fellow of quantum hardware at Microsoft, said he believed the developments would shake up conventional thinking about the future of quantum computers.

“Many people have said that quantum computing, that is to say useful quantum computers, are decades away,” he said. “I think that this brings us into years rather than decades.”

Travis Humble, director of the Quantum Science Center of Oak Ridge National Laboratory in the US, said he agreed Microsoft would now be able to deliver prototypes faster – but warned there remained work to do.

“The long term goals for solving industrial applications on quantum computers will require scaling up these prototypes even further,” he said.

While rivals produced a steady stream of announcements – notably Google’s “Willow” at the end of 2024 – Microsoft seemed to be taking longer.

Pursuing this approach was, in the company’s own words, a “high-risk, high-rewards” strategy, but one it now believes is going to pay off.

If you have the time, do read Vallance’s February 19, 2025 article.

The research paper

Purdue University’s (Indiana, US) February 25, 2025 news release on EurekAlert announces publication of the research, Note: Links have been removed,

Microsoft Quantum published an article in Nature on Feb. 19 [2025] detailing recent advances in the measurement of quantum devices that will be needed to realize a topological quantum computer. Among the authors are Microsoft scientists and engineers who conduct research at Microsoft Quantum Lab West Lafayette, located at Purdue University. In an announcement by Microsoft Quantum, the team describes the operation of a device that is a necessary building block for a topological quantum computer. The published results are an important milestone along the path to construction of quantum computers that are potentially more robust and powerful than existing technologies.

“Our hope for quantum computation is that it will aid chemists, materials scientists and engineers working on the design and manufacturing of new materials that are so important to our daily lives,” said Michael Manfra, scientific director of Microsoft Quantum Lab West Lafayette and the Bill and Dee O’Brien Distinguished Professor of Physics and Astronomy, professor of materials engineering, and professor of electrical and computer engineering at Purdue. “The promise of quantum computation is in accelerating scientific discovery and its translation into useful technology. For example, if quantum computers reduce the time and cost to produce new lifesaving therapeutic drugs, that is real societal impact.” 

The Microsoft Quantum Lab West Lafayette team advanced the complex layered materials that make up the quantum plane of the full device architecture used in the tests. Microsoft scientists working with Manfra are experts in advanced semiconductor growth techniques, including molecular beam epitaxy, that are used to build low-dimensional electron systems that form the basis for quantum bits, or qubits. They built the semiconductor and superconductor layers with atomic layer precision, tailoring the material’s properties to those needed for the device architecture.

Manfra, a member of the Purdue Quantum Science and Engineering Institute, credited the strong relationship between Purdue and Microsoft, built over the course of a decade, with the advances conducted at Microsoft Quantum Lab West Lafayette. In 2017 Purdue deepened its relationship with Microsoft with a multiyear agreement that includes embedding Microsoft employees with Manfra’s research team at Purdue.

“This was a collaborative effort by a very sophisticated team, with a vital contribution from the Microsoft scientists at Purdue,” Manfra said. “It’s a Microsoft team achievement, but it’s also the culmination of a long-standing partnership between Purdue and Microsoft. It wouldn’t have been possible without an environment at Purdue that was conducive to this mode of work — I attempted to blend industrial with academic research to the betterment of both communities. I think that’s a success story.”

Quantum science and engineering at Purdue is a pillar of the Purdue Computes initiative, which is focused on advancing research in computing, physical AI, semiconductors and quantum technologies.

“This research breakthrough in the measurement of the state of quasi particles is a milestone in the development of topological quantum computing, and creates a watershed moment in the semiconductor-superconductor hybrid structure,” Purdue President Mung Chiang said. “Marking also the latest success in the strategic initiative of Purdue Computes, the deep collaboration that Professor Manfra and his team have created with the Microsoft Quantum Lab West Lafayette on the Purdue campus exemplifies the most impactful industry research partnership at any American university today.”

Most approaches to quantum computers rely on local degrees of freedom to encode information. The spin of an electron is a classic example of a qubit. But an individual spin is prone to disturbance — by relatively common things like heat, vibrations or interactions with other quantum particles — which can corrupt quantum information stored in the qubit, necessitating a great deal of effort in detecting and correcting errors. Instead of spin, topological quantum computers store information in a more distributed manner; the qubit state is encoded in the state of many particles acting in concert. Consequently, it is harder to scramble the information as the state of all the particles must be changed to alter the qubit state.

In the Nature paper, the Microsoft team was able to accurately and quickly measure the state of quasi particles that form the basis of the qubit.

“The device is used to measure a basic property of a topological qubit quickly,” Manfra said. “The team is excited to build on these positive results.”

“The team in West Lafayette pushed existing epitaxial technology to a new state-of-the-art for semiconductor-superconductor hybrid structures to ensure a perfect interface between each of the building blocks of the Microsoft hybrid system,” said Sergei Gronin, a Microsoft Quantum Lab scientist.

“The materials quality that is required for quantum computing chips necessitates constant improvements, so that’s one of the biggest challenges,” Gronin said. “First, we had to adjust and improve semiconductor technology to meet a new level that nobody was able to achieve before. But equally important was how to create this hybrid system. To do that, we had to merge a semiconducting part and a superconducting part. And that means you need to perfect the semiconductor and the superconductor and perfect the interface between them.”

While work discussed in the Nature article was performed by Microsoft employees, the exposure to industrial-scale research and development is an outstanding opportunity for Purdue students in Manfra’s academic group as well. John Watson, Geoffrey Gardner and Saeed Fallahi, who are among the coauthors of the paper, earned their doctoral degrees under Manfra and now work for Microsoft Quantum at locations in Redmond, Washington, and Copenhagen, Denmark. Most of Manfra’s former students now work for quantum computing companies, including Microsoft. Tyler Lindemann, who works in the West Lafayette lab and helped to build the hybrid semiconductor-superconductor structures required for the device, is earning a doctoral degree from Purdue under Manfra’s supervision.

“Working in Professor Manfra’s lab in conjunction with my work for Microsoft Quantum has given me a head start in my professional development, and been fruitful for my academic work,” Lindemann said. “At the same time, many of the world-class scientists and engineers at Microsoft Quantum have some background in academia, and being able to draw from their knowledge and experience is an indispensable resource in my graduate studies. From both perspectives, it’s a great opportunity.”

Here’s a link to and a citation for the paper,

Interferometric single-shot parity measurement in InAs–Al hybrid devices by Microsoft Azure Quantum, Morteza Aghaee, Alejandro Alcaraz Ramirez, Zulfi Alam, Rizwan Ali, Mariusz Andrzejczuk, Andrey Antipov, Mikhail Astafev, Amin Barzegar, Bela Bauer, Jonathan Becker, Umesh Kumar Bhaskar, Alex Bocharov, Srini Boddapati, David Bohn, Jouri Bommer, Leo Bourdet, Arnaud Bousquet, Samuel Boutin, Lucas Casparis, Benjamin J. Chapman, Sohail Chatoor, Anna Wulff Christensen, Cassandra Chua, Patrick Codd, William Cole, Paul Cooper, Fabiano Corsetti, Ajuan Cui, Paolo Dalpasso, Juan Pablo Dehollain, Gijs de Lange, Michiel de Moor, Andreas Ekefjärd, Tareq El Dandachi, Juan Carlos Estrada Saldaña, Saeed Fallahi, Luca Galletti, Geoff Gardner, Deshan Govender, Flavio Griggio, Ruben Grigoryan, Sebastian Grijalva, Sergei Gronin, Jan Gukelberger, Marzie Hamdast, Firas Hamze, Esben Bork Hansen, Sebastian Heedt, Zahra Heidarnia, Jesús Herranz Zamorano, Samantha Ho, Laurens Holgaard, John Hornibrook, Jinnapat Indrapiromkul, Henrik Ingerslev, Lovro Ivancevic, Thomas Jensen, Jaspreet Jhoja, Jeffrey Jones, Konstantin V. Kalashnikov, Ray Kallaher, Rachpon Kalra, Farhad Karimi, Torsten Karzig, Evelyn King, Maren Elisabeth Kloster, Christina Knapp, Dariusz Kocon, Jonne V. Koski, Pasi Kostamo, Mahesh Kumar, Tom Laeven, Thorvald Larsen, Jason Lee, Kyunghoon Lee, Grant Leum, Kongyi Li, Tyler Lindemann, Matthew Looij, Julie Love, Marijn Lucas, Roman Lutchyn, Morten Hannibal Madsen, Nash Madulid, Albert Malmros, Michael Manfra, Devashish Mantri, Signe Brynold Markussen, Esteban Martinez, Marco Mattila, Robert McNeil, Antonio B. Mei, Ryan V. Mishmash, Gopakumar Mohandas, Christian Mollgaard, Trevor Morgan, George Moussa, Chetan Nayak, Jens Hedegaard Nielsen, Jens Munk Nielsen, William Hvidtfelt Padkar Nielsen, Bas Nijholt, Mike Nystrom, Eoin O’Farrell, Thomas Ohki, Keita Otani, Brian Paquelet Wütz, Sebastian Pauka, Karl Petersson, Luca Petit, Dima Pikulin, Guen Prawiroatmodjo, Frank Preiss, Eduardo Puchol Morejon, Mohana Rajpalke, Craig Ranta, Katrine Rasmussen, David Razmadze, Outi Reentila, David J. Reilly, Yuan Ren, Ken Reneris, Richard Rouse, Ivan Sadovskyy, Lauri Sainiemi, Irene Sanlorenzo, Emma Schmidgall, Cristina Sfiligoj, Mustafeez Bashir Shah, Kevin Simoes, Shilpi Singh, Sarat Sinha, Thomas Soerensen, Patrick Sohr, Tomas Stankevic, Lieuwe Stek, Eric Stuppard, Henri Suominen, Judith Suter, Sam Teicher, Nivetha Thiyagarajah, Raj Tholapi, Mason Thomas, Emily Toomey, Josh Tracy, Michelle Turley, Shivendra Upadhyay, Ivan Urban, Kevin Van Hoogdalem, David J. Van Woerkom, Dmitrii V. Viazmitinov, Dominik Vogel, John Watson, Alex Webster, Joseph Weston, Georg W. Winkler, Di Xu, Chung Kai Yang, Emrah Yucelen, Roland Zeisel, Guoji Zheng & Justin Zilke. Nature 638, 651–655 (2025). DOI: https://doi.org/10.1038/s41586-024-08445-2 Published online: 19 February 2025 Issue Date: 20 February 2025

This paper is open access. Note: I usually tag all of the authors but not this time.

Controversy over this and previous Microsoft quantum computing claims

Elizabeth Hlavinka’s March 17, 2025 article for Salon.com provides an overview, Note: Links have been removed,

The matter making up the world around us has long-since been organized into three neat categories: solids, liquids and gases. But last month [February 2025], Microsoft announced that it had allegedly discovered another state of matter originally theorized to exist in 1937. 

This new state of matter called the Majorana zero mode is made up of quasiparticles, which act as their own particle and antiparticle. The idea is that the Majorana zero mode could be used to build a quantum computer, which could help scientists answer complex questions that standard computers are not capable of solving, with implications for medicine, cybersecurity and artificial intelligence.

In late February [2025], Sen. Ted Cruz presented Microsoft’s new computer chip at a congressional hearing, saying, “Technologies like this new chip I hold in the palm of my hand, the Majorana 1 quantum chip, are unlocking a new era of computing that will transform industries from health care to energy, solving problems that today’s computers simply cannot.”

However, Microsoft’s announcement, claiming a “breakthrough in quantum computing,” was met with skepticism from some physicists in the field. Proving that this form of quantum computing can work requires first demonstrating the existence of Majorana quasiparticles, measuring what the Majorana particles are doing, and creating something called a topological qubit used to store quantum information.

But some say that not all of the data necessary to prove this has been included in the research paper published in Nature, on which this announcement is based. And due to a fraught history of similar claims from the company being disputed and ultimately rescinded, some are extra wary of the results. [emphasis mine]

It’s not the first time Microsoft has faced backlash from presenting findings in the field. In 2018, the company reported that they had detected the presence of Majorana zero-modes in a research paper, but it was retracted by Nature, the journal that published it after a report from independent experts put their findings under more intense scrutiny.

In the [2018] report, four physicists not involved in the research concluded that it did not appear that Microsoft had intentionally misrepresented the data, but instead seemed to be “caught up in the excitement of the moment [emphasis mine].”

Establishing the existence of these particles is extremely complex in part because disorder in the device can create signals that mimic these quasiparticles when they are not actually there. 

Modern computers in use today are encoded in bits, which can either be in a zero state (no current flowing through them), or a one state (current flowing.) These bits work together to send information and signals that communicate with the computer, powering everything from cell phones to video games.

Companies like Google, IBM and Amazon have invested in designing another form of quantum computer that uses chips built with “qubits,” or quantum bits. Qubits can exist in both zero and one states at the same time due to a phenomenon called superposition. 

However, qubits are subject to external noise from the environment that can affect their performance, said Dr. Paolo Molignini, a researcher in theoretical quantum physics at Stockholm University.

“Because qubits are in a superposition of zero and one, they are very prone to errors and they are very prone to what is called decoherence, which means there could be noise, thermal fluctuations or many things that can collapse the state of the qubits,” Molignini told Salon in a video call. “Then you basically lose all of the information that you were encoding.”

In December [2024], Google said its quantum computer could perform a calculation that a standard computer could complete in 10 septillion years — a period far longer than the age of the universe — in just under five minutes.

However, a general-purpose computer would require billions of qubits, so these approaches are still a far cry from having practical applications, said Dr. Patrick Lee, a physicist at the Massachusetts Institute of Technology [MIT], who co-authored the report leading to the 2018 Nature paper’s retraction.

Microsoft is taking a different approach to quantum computing by trying to develop  a topological qubit, which has the ability to store information in multiple places at once. Topological qubits exist within the Majorana zero states and are appealing because they can theoretically offer greater protection against environmental noise that destroys information within a quantum system.

Think of it like an arrow, where the arrowhead holds a portion of the information and the arrow tail holds the rest, Lee said. Distributing information across space like this is called topological protection.

“If you are able to put them far apart from each other, then you have a chance of maintaining the identity of the arrow even if it is subject to noise,” Lee told Salon in a phone interview. “The idea is that if the noise affects the head, it doesn’t kill the arrow and if it affects only the tail it doesn’t kill your arrow. It has to affect both sides simultaneously to kill your arrow, and that is very unlikely if you are able to put them apart.”

… Lee believes that even if the data doesn’t entirely prove that topological qubits exist in the Majorana zero-state, it still represents a scientific advancement. But he noted that several important issues need to be solved before it has practical implications. For one, the coherence time of these particles — or how long they can exist without being affected by environmental noise — is still very short, he explained.

“They make a measurement, come back, and the qubit has changed, so you have lost your coherence,” Lee said. “With this very short time, you cannot do anything with it.”

“I just wish they [Microsoft] were a bit more careful with their claims because I fear that if they don’t measure up to what they are saying, there might be a backlash at some point where people say, ‘You promised us all these fancy things and where are they now?’” Molignini said. “That might damage the entire quantum community, not just themselves.”

Iif you have the time, please read Hlavinka’s March 17, 2025 article in its entirety .

D-Wave Quantum Systems claims quantum supremacy over real world problem solution

A March 15, 2025 article by Bob Yirka for phys.org announces the news from D-Wave Quantum Systems. Note: The company, which had its headquarters in Canada (Burnaby, BC) now seems to be a largely US company with its main headquarters in Palo Alto, California and an ancillary or junior (?) headquarters in Canada, Note: A link has been removed,

A team of quantum computer researchers at quantum computer maker D-Wave, working with an international team of physicists and engineers, is claiming that its latest quantum processor has been used to run a quantum simulation faster than could be done with a classical computer.

In their paper published in the journal Science, the group describes how they ran a quantum version of a mathematical approximation regarding how matter behaves when it changes states, such as from a gas to a liquid—in a way that they claim would be nearly impossible to conduct on a traditional computer.

Here’s a March 12, 2025 D-Wave Systems (now D-Wave Quantum Systems) news release touting its real world problem solving quantum supremacy,

New landmark peer-reviewed paper published in Science, “Beyond-Classical Computation in Quantum Simulation,” unequivocally validates D-Wave’s achievement of the world’s first and only demonstration of quantum computational supremacy on a useful, real-world problem

Research shows D-Wave annealing quantum computer performs magnetic materials simulation in minutes that would take nearly one million years and more than the world’s annual electricity consumption to solve using a classical supercomputer built with GPU clusters

D-Wave Advantage2 annealing quantum computer prototype used in supremacy achievement, a testament to the system’s remarkable performance capabilities

PALO ALTO, Calif. – March 12, 2025 – D-Wave Quantum Inc. (NYSE: QBTS) (“D-Wave” or the “Company”), a leader in quantum computing systems, software, and services and the world’s first commercial supplier of quantum computers, today announced a scientific breakthrough published in the esteemed journal Science, confirming that its annealing quantum computer outperformed one of the world’s most powerful classical supercomputers in solving complex magnetic materials simulation problems with relevance to materials discovery. The new landmark peer-reviewed paper, Beyond-Classical Computation in Quantum Simulation,” validates this achievement as the world’s first and only demonstration of quantum computational supremacy on a useful problem.

An international collaboration of scientists led by D-Wave performed simulations of quantum dynamics in programmable spin glasses—computationally hard magnetic materials simulation problems with known applications to business and science—on both D-Wave’s Advantage2TM prototype annealing quantum computer and the Frontier supercomputer at the Department of Energy’s Oak Ridge National Laboratory. The work simulated the behavior of a suite of lattice structures and sizes across a variety of evolution times and delivered a multiplicity of important material properties. D-Wave’s quantum computer performed the most complex simulation in minutes and with a level of accuracy that would take nearly one million years using the supercomputer. In addition, it would require more than the world’s annual electricity consumption to solve this problem using the supercomputer, which is built with graphics processing unit (GPU) clusters.

“This is a remarkable day for quantum computing. Our demonstration of quantum computational supremacy on a useful problem is an industry first. All other claims of quantum systems outperforming classical computers have been disputed or involved random number generation of no practical value,” said Dr. Alan Baratz, CEO of D-Wave. “Our achievement shows, without question, that D-Wave’s annealing quantum computers are now capable of solving useful problems beyond the reach of the world’s most powerful supercomputers. We are thrilled that D-Wave customers can use this technology today to realize tangible value from annealing quantum computers.”

Realizing an Industry-First Quantum Computing Milestone
The behavior of materials is governed by the laws of quantum physics. Understanding the quantum nature of magnetic materials is crucial to finding new ways to use them for technological advancement, making materials simulation and discovery a vital area of research for D-Wave and the broader scientific community. Magnetic materials simulations, like those conducted in this work, use computer models to study how tiny particles not visible to the human eye react to external factors. Magnetic materials are widely used in medical imaging, electronics, superconductors, electrical networks, sensors, and motors.

“This research proves that D-Wave’s quantum computers can reliably solve quantum dynamics problems that could lead to discovery of new materials,” said Dr. Andrew King, senior distinguished scientist at D-Wave. “Through D-Wave’s technology, we can create and manipulate programmable quantum matter in ways that were impossible even a few years ago.”

Materials discovery is a computationally complex, energy-intensive and expensive task. Today’s supercomputers and high-performance computing (HPC) centers, which are built with tens of thousands of GPUs, do not always have the computational processing power to conduct complex materials simulations in a timely or energy-efficient manner. For decades, scientists have aspired to build a quantum computer capable of solving complex materials simulation problems beyond the reach of classical computers. D-Wave’s advancements in quantum hardware have made it possible for its annealing quantum computers to process these types of problems for the first time.

“This is a significant milestone made possible through over 25 years of research and hardware development at D-Wave, two years of collaboration across 11 institutions worldwide, and more than 100,000 GPU and CPU hours of simulation on one of the world’s fastest supercomputers as well as computing clusters in collaborating institutions,” said Dr. Mohammad Amin, chief scientist at D-Wave. “Besides realizing Richard Feynman’s vision of simulating nature on a quantum computer, this research could open new frontiers for scientific discovery and quantum application development.” 

Advantage2 System Demonstrates Powerful Performance Gains
The results shown in “Beyond-Classical Computation in Quantum Simulation” were enabled by D-Wave’s previous scientific milestones published in Nature Physics (2022) and Nature (2023), which theoretically and experimentally showed that quantum annealing provides a quantum speedup in complex optimization problems. These scientific advancements led to the development of the Advantage2 prototype’s fast anneal feature, which played an essential role in performing the precise quantum calculations needed to demonstrate quantum computational supremacy.

“The broader quantum computing research and development community is collectively building an understanding of the types of computations for which quantum computing can overtake classical computing. This effort requires ongoing and rigorous experimentation,” said Dr. Trevor Lanting, chief development officer at D-Wave. “This work is an important step toward sharpening that understanding, with clear evidence of where our quantum computer was able to outperform classical methods. We believe that the ability to recreate the entire suite of results we produced is not possible classically. We encourage our peers in academia to continue efforts to further define the line between quantum and classical capabilities, and we believe these efforts will help drive the development of ever more powerful quantum computing technology.”

The Advantage2 prototype used to achieve quantum computational supremacy is available for customers to use today via D-Wave’s Leap™ real-time quantum cloud service. The prototype provides substantial performance improvements from previous-generation Advantage systems, including increased qubit coherence, connectivity, and energy scale, which enables higher-quality solutions to larger, more complex problems. Moreover, D-Wave now has an Advantage2 processor that is four times larger than the prototype used in this work and has extended the simulations of this paper from hundreds of qubits to thousands of qubits, which are significantly larger than those described in this paper.

Leading Industry Voices Echo Support
Dr. Hidetoshi Nishimori, Professor, Department of Physics, Tokyo Institute of Technology:
“This paper marks a significant milestone in demonstrating the real-world applicability of large-scale quantum computing. Through rigorous benchmarking of quantum annealers against state-of-the-art classical methods, it convincingly establishes a quantum advantage in tackling practical problems, revealing the transformative potential of quantum computing at an unprecedented scale.”

Dr. Seth Lloyd, Professor of Quantum Mechanical Engineering, MIT:
Although large-scale, fully error-corrected quantum computers are years in the future, quantum annealers can probe the features of quantum systems today. In an elegant paper, the D-Wave group has used a large-scale quantum annealer to uncover patterns of entanglement in a complex quantum system that lie far beyond the reach of the most powerful classical computer. The D-Wave result shows the promise of quantum annealers for exploring exotic quantum effects in a wide variety of systems.”

Dr. Travis Humble, Director of Quantum Science Center, Distinguished Scientist at Oak Ridge National Laboratory:
“ORNL seeks to expand the frontiers of computation through many different avenues, and benchmarking quantum computing for materials science applications provides critical input to our understanding of new computational capabilities.”

Dr. Juan Carrasquilla, Associate Professor at the Department of Physics, ETH Zürich:
“I believe these results mark a critical scientific milestone for D-Wave. They also serve as an invitation to the scientific community, as these results offer a strong benchmark and motivation for developing novel simulation techniques for out-of-equilibrium dynamics in quantum many-body physics. Furthermore, I hope these findings encourage theoretical exploration of the computational challenges involved in performing such simulations, both classically and quantum-mechanically.”

Dr. Victor Martin-Mayor, Professor of Theoretical Physics, Universidad Complutense de Madrid:
“This paper is not only a tour-de-force for experimental physics, it is also remarkable for the clarity of the results. The authors have addressed a problem that is regarded both as important and as very challenging to a classical computer. The team has shown that their quantum annealer performs better at this task than the state-of-the-art methods for classical simulation.”

Dr. Alberto Nocera, Senior Staff Scientist, The University of British Columbia:
“Our work shows the impracticability of state-of-the-art classical simulations to simulate the dynamics of quantum magnets, opening the door for quantum technologies based on analog simulators to solve scientific questions that may otherwise remain unanswered using conventional computers.”

About D-Wave Quantum Inc.
D-Wave is a leader in the development and delivery of quantum computing systems, software, and services. We are the world’s first commercial supplier of quantum computers, and the only company building both annealing and gate-model quantum computers. Our mission is to help customers realize the value of quantum, today. Our 5,000+ qubit Advantage™ quantum computers, the world’s largest, are available on-premises or via the cloud, supported by 99.9% availability and uptime. More than 100 organizations trust D-Wave with their toughest computational challenges. With over 200 million problems submitted to our Advantage systems and Advantage2™ prototypes to date, our customers apply our technology to address use cases spanning optimization, artificial intelligence, research and more. Learn more about realizing the value of quantum computing today and how we’re shaping the quantum-driven industrial and societal advancements of tomorrow: www.dwavequantum.com.

Forward-Looking Statements
Certain statements in this press release are forward-looking, as defined in the Private Securities Litigation Reform Act of 1995. These statements involve risks, uncertainties, and other factors that may cause actual results to differ materially from the information expressed or implied by these forward-looking statements and may not be indicative of future results. These forward-looking statements are subject to a number of risks and uncertainties, including, among others, various factors beyond management’s control, including the risks set forth under the heading “Risk Factors” discussed under the caption “Item 1A. Risk Factors” in Part I of our most recent Annual Report on Form 10-K or any updates discussed under the caption “Item 1A. Risk Factors” in Part II of our Quarterly Reports on Form 10-Q and in our other filings with the SEC. Undue reliance should not be placed on the forward-looking statements in this press release in making an investment decision, which are based on information available to us on the date hereof. We undertake no duty to update this information unless required by law.

Here’s a link to and a citation for the most recent paper,

Beyond-classical computation in quantum simulation by Andrew D. King , Alberto Nocera, Marek M. Rams, Jacek Dziarmaga, Roeland Wiersema, William Bernoudy, Jack Raymond, Nitin Kaushal, Niclas Heinsdorf, Richard Harris, Kelly Boothby, Fabio Altomare, Mohsen Asad, Andrew J. Berkley, Martin Boschnak, Kevin Chern, Holly Christiani, Samantha Cibere, Jake Connor, Martin H. Dehn, Rahul Deshpande, Sara Ejtemaee, Pau Farre, Kelsey Hamer, Emile Hoskinson, Shuiyuan Huang, Mark W. Johnson, Samuel Kortas, Eric Ladizinsky, Trevor Lanting, Tony Lai, Ryan Li, Allison J. R. MacDonald, Gaelen Marsden, Catherine C. McGeoch, Reza Molavi, Travis Oh, Richard Neufeld, Mana Norouzpour, Joel Pasvolsky, Patrick Poitras, Gabriel Poulin-Lamarre, Thomas Prescott, Mauricio Reis, Chris Rich, Mohammad Samani, Benjamin Sheldan, Anatoly Smirnov, Edward Sterpka, Berta Trullas Clavera, Nicholas Tsai, Mark Volkmann, Alexander M. Whiticar, Jed D. Whittaker, Warren Wilkinson, Jason Yao, T.J. Yi, Anders W. Sandvik, Gonzalo Alvarez, Roger G. Melko, Juan Carrasquilla, Marcel Franz, and Mohammad H. Amin. Science 12 Mar 2025 First Release DOI: 10.1126/science.ado6285

This paper appears to be open access.Note: I usually tag all of the authors but not this time either.

A controversy of sorts

Madison McLauchlan’s March 19, 2025 article for Betakit (website for Canadian Startup News & Tech Innovation), Note: Links have been removed,

Canadian-born company D-Wave Quantum Systems said it achieved “quantum supremacy” last week after publishing what it calls a groundbreaking paper in the prestigious journal Science. Despite the lofty term, Canadian experts say supremacy is not the be-all, end-all of quantum innovation. 

D-Wave, which has labs in Palo Alto, Calif., and Burnaby, BC, claimed in a statement that it has shown “the world’s first and only demonstration of quantum computational supremacy on a useful, real-world problem.”

Coined in the early 2010s by physicist John Preskill, quantum supremacy is the ability of a quantum computing system to solve a problem no classical computer can in a feasible amount of time. The metric makes no mention of whether the problem needs to be useful or relevant to real life. Google researchers published a paper in Nature in 2019 claiming they cleared that bar with the Sycamore quantum processor. Researchers at the University of Science and Technology in China claimed they demonstrated quantum supremacy several times. 

D-Wave’s attempt differs in that its researchers aimed to solve a real-world materials-simulation problem with quantum computing—one the company claims would be nearly impossible for a traditional computer to solve in a reasonable amount of time. D-Wave used an annealing designed to solve optimization problems. The problem is represented like an energy space, where the “lowest energy state” corresponds to the solution. 

While exciting, quantum supremacy is just one metric among several that mark the progress toward widely useful quantum computers, industry experts told BetaKit. 

“It is a very important and mostly academic metric, but certainly not the most important in the grand scheme of things, as it doesn’t take into account the usefulness of the algorithm,” said Martin Laforest, managing partner at Quantacet, a specialized venture capital fund for quantum startups. 

He added that Google and Xanadu’s [Xanadu Quantum Technologies based in Toronto, Canada] past claims to quantum supremacy were “extraordinary pieces of work, but didn’t unlock practicality.” 

Laforest, along with executives at Canadian quantum startups Nord Quantique and Photonic, say that the milestones of ‘quantum utility’ or ‘quantum advantage’ may be more important than supremacy. 

According to Quantum computing company Quera [QuEra?], quantum advantage is the demonstration of a quantum algorithm solving a real-world problem on a quantum computer faster than any classical algorithm running on any classical computer. On the other hand, quantum utility, according to IBM, refers to when a quantum computer is able to perform reliable computations at a scale beyond brute-force classical computing methods that provide exact solutions to computational problems. 

Error correction hasn’t traditionally been considered a requirement for quantum supremacy, but Laforest told BetaKit the term is “an ever-moving target, constantly challenged by advances in classical algorithms.” He added: “In my opinion, some level of supremacy or utility may be possible in niche areas without error correction, but true disruption requires it.”

Paul Terry, CEO of Vancouver-based Photonic, thinks that though D-Wave’s claim to quantum supremacy shows “continued progress to real value,” scalability is the industry’s biggest hurdle to overcome.

But as with many milestone claims in the quantum space, D-Wave’s latest innovation has been met with scrutiny from industry competitors and researchers on the breakthrough’s significance, claiming that classical computers have achieved similar results. Laforest echoed this sentiment.

“Personally, I wouldn’t say it’s an unequivocal demonstration of supremacy, but it is a damn nice experiment that once again shows the murky zone between traditional computing and early quantum advantage,” Laforest said.

Originally founded out of the University of British Columbia, D-Wave went public on the New York Stock Exchange just over two years ago through a merger with a special-purpose acquisition company in 2022. D-Wave became a Delaware-domiciled corporation as part of the deal.

Earlier this year, D-Wave’s stock price dropped after Nvidia CEO Jensen Huang publicly stated that he estimated that useful quantum computers were more than 15 years away. D-Wave’s stock price, which had been struggling, has seen a considerable bump in recent months alongside a broader boost in the quantum market. The price popped after its most recent earnings, shared right after its quantum supremacy announcement. 

The beat goes on

Some of this is standard in science. There’s always a debate over big claims and it’s not unusual for people to get over excited and have to make a retraction. Scientists are people too. That said, there’s a lot of money on the line and that appears to be making situation even more volatile than usual.

That last paragraph was completed on the morning of March 21, 2025 and later that afternoon I came across this March 21, 2025 article by Michael Grothaus for Fast Company, Note: Links have been removed,

Quantum computing stocks got pummeled yesterday, with the four most prominent public quantum computing companies—IonQ, Rigetti Computing, Quantum Computing Inc., and D-Wave Quantum Inc.—falling anywhere from over 9% to over 18%. The reason? A lot of it may have to do with AI chip giant Nvidia. Again.

Stocks crash yesterday on Nvidia quantum news

Yesterday was a bit of a bloodbath on the stock market for the four most prominent publicly traded quantum computing companies. …

All four of these quantum computing stocks [IonQ, Inc.; Rigetti Computing, Inc.; Quantum Computing Inc.; D-Wave Quantum Inc.] tumbled on the day that AI chip giant Nvidia kicked off its two-day Quantum Day event. In a blog post from January 14 announcing Quantum Day, Nvidia said the event “brings together leading experts for a comprehensive and balanced perspective on what businesses should expect from quantum computing in the coming decades — mapping the path toward useful quantum applications.”

Besides bringing quantum experts together, the AI behemoth also announced that it will be launching a new quantum computing research center in Boston.

Called the NVIDIA Accelerated Quantum Research Center (NVAQC), the new research lab “will help solve quantum computing’s most challenging problems, ranging from qubit noise to transforming experimental quantum processors into practical devices,” the company said in a press release.

The NVAQC’s location in Boston means it will be near both Harvard University and the Massachusetts Institute of Technology (MIT). 

Before Nvidia’s announcement yesterday, IonQ, Rigetti, D-Wave, and Quantum Computing Inc. were the leaders in the nascent field of quantum computing. And while they still are right now (Nvidia’s quantum research lab hasn’t been built yet), the fear is that Nvidia could use its deep pockets to quickly buy its way into a leadership spot in the field. With its $2.9 trillion market cap, the company can easily afford to throw billions of research dollars into quantum computing.

As noted by the Motley Fool, the location of the NVIDIA Accelerated Quantum Research Center in Boston will also allow Nvidia to more easily tap into top quantum talent from Harvard and MIT—talent that may have otherwise gone to IonQ, Rigetti, D-Wave, and Quantum Computing Inc.

Nvidia’s announcement is a massive about-face from the company in regard to how it views quantum computing. It’s also the second time that Nvidia has caused quantum stocks to crash this year. Back in January, shares in prominent quantum computing companies fell after Huang said that practical use of quantum computing was decades away.

Those comments were something quantum computing company CEOs like D-Wave’s Alan Baratz took issue with. “It’s an egregious error on Mr. Huang’s part,” Bartaz told Fast Company at the time. “We’re not decades away from commercial quantum computers. They exist. There are companies that are using our quantum computer today.”

According to Investor’s Business Daily, Huang reportedly got the idea for Nvidia’s Quantum Day event after the blowback to his comments, inviting quantum computing executives to the event to explain why he was incorrect about quantum computing.

The word is volatile.

Do nanostructures in the deep ocean floor hint at life’s origin?

A September 25, 2024 news item on phys.org describes a ‘nano’ discovery on the ocean floor, Note: Links have been removed,

Researchers led by Ryuhei Nakamura at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan and The Earth-Life Science Institute (ELSI) of Tokyo Institute of Technology have discovered inorganic nanostructures surrounding deep-ocean hydrothermal vents that are strikingly similar to molecules that make life as we know it possible. These nanostructures are self-organized and act as selective ion channels, which create energy that can be harnessed in the form of electricity.

Published Sept. 25 [2024] in Nature Communications, the findings impact not only our understanding of how life began, but can also be applied to industrial blue-energy harvesting.

An October 3, 2024 Riken press release (also on EurekAlert but published on September 25, 2024), which originated the news item, delves further into the research,

When seawater seeps way down into the Earth through cracks in the ocean floor, it gets heated by magma, rises back up to the surface, and is released back into the ocean through fissures called hydrothermal vents. The rising hot water contains dissolved minerals gained from its time deep in the Earth, and when it meets the cool ocean water, chemical reactions force the mineral ions out of the water where they form solid structures around the vent called precipitates.

Hydrothermal vents are thought to be the birthplace of life on Earth because they provide the necessary conditions: they are stable, rich in minerals, and contain sources of energy. Much of life on Earth relies on osmotic energy, which is created by ion gradients—the difference in salt and proton concentration—between the inside and outside of living cells. The RIKEN CSRS researchers were studying serpentinite-hosted hydrothermal vents because this kind of vent has mineral precipitates with a very complex layered structure formed from metal oxides, hydroxides, and carbonates. “Unexpectedly, we discovered that osmotic energy conversion, a vital function in modern plant, animal, and microbial life , can occur abiotically in a geological environment,” says Nakamura.

The researchers were studying samples collected from the Shinkai Seep Field, located in the Pacific Ocean’s Mariana Trench at a depth of 5743 m. The key sample was an 84-cm piece composed mostly of brucite. Optical microscopes and scans with micrometer-sized X-ray beams revealed that brucite crystals were arranged in continuous columns that acted as nano-channels for the vent fluid. The researchers noticed that the surface of the precipitate was electrically charged, and that the size and direction of the charge—positive or negative—varied across the surface. Knowing that structured nanopores with variable charge are the hallmarks of osmotic energy conversion, they next tested whether osmotic energy conversion was indeed occurring naturally in the inorganic deep-sea rock.

The team used an electrode to record the current-voltage of the samples. When the samples were exposed to high concentrations of potassium chloride, the conductance was proportional to the salt concentration at the surface of the nanopores. But at lower concentrations, the conductance was constant, not proportional, and was determined by the local electrical charge of the precipitate’s surface. This charge-governed ion transport is very similar to voltage-gated ion channels observed in living cells like neurons.

By testing the samples with chemical gradients that exist in the deep ocean from where they were extracted, the researchers were able to show that the nanopores act as selective ion channels. At locations with carbonate adhered to the surface, the nanopores allowed positive sodium ions to flow through. However, at nanopores with calcium adhered to the surface, the pores only allowed negative chloride ions to pass through.

“The spontaneous formation of ion channels discovered in deep-sea hydrothermal vents has direct implications for the origin of life on Earth and beyond,” says Nakamura. “In particular, our study shows how osmotic energy conversion, a vital function in modern life, can occur abiotically in a geological environment.”

Industrial power plants use salinity gradients between seawater and river water to generate energy, a process called blue-energy harvesting. According to Nakamura, understanding how nanopore structure is spontaneously generated in the hydrothermal vents could help engineers devise better synthetic methods for generating electrical energy from osmotic conversion.

Here’s a link to and a citation for the paper,

Osmotic energy conversion in serpentinite-hosted deep-sea hydrothermal vents by Hye-Eun Lee, Tomoyo Okumura, Hideshi Ooka, Kiyohiro Adachi, Takaaki Hikima, Kunio Hirata, Yoshiaki Kawano, Hiroaki Matsuura, Masaki Yamamoto, Masahiro Yamamoto, Akira Yamaguchi, Ji-Eun Lee, Hiroya Takahashi, Ki Tae Nam, Yasuhiko Ohara, Daisuke Hashizume, Shawn Erin McGlynn & Ryuhei Nakamura. Nature Communications volume 15, Article number: 8193 (2024) DOI: https://doi.org/10.1038/s41467-024-52332-3 Published: 25 September 2024

This paper is open access.

A graphene joke (of sorts): What did the electron ‘say’ to the phonon in the graphene sandwich?

Unfortunately, there isn’t a punch line but I appreciate the effort to inject a little lightness into the description of a fairly technical achievement, from a February 12, 2024 news item on Nanowerk, Note: A link has been removed,

Electrons carry electrical energy, while vibrational energy is carried by phonons. Understanding how they interact with each other in certain materials, like in a sandwich of two graphene layers, will have implications for future optoelectronic devices.

Key Takeaways

Twisted graphene layers exhibit unique electrical properties.

Electron-phonon interactions crucial for energy loss in graphene.

Discovery of a new physical process involving electron-phonon Umklapp scattering.

Potential implications for ultrafast optoelectronics and quantum applications.

A February 9, 2024 Eindhoven University of Technology (TU/e; Netherlands) press release, which originated the news item, is reproduced here in its entirety, Note: Links have been removed,

Electrons carry electrical energy, while vibrational energy is carried by phonons. Understanding how they interact with each other in certain materials, like in a sandwich of two graphene layers, will have implications for future optoelectronic devices. Recent work has revealed that graphene layers twisted relative to each other by a small ‘magic angle’ can act as perfect insulator or superconductor. But the physics of the electron-phonon interactions are a mystery. As part of a worldwide international collaboration, TU/e researcher Klaas-Jan Tielrooij has led a study on electron-phonon interactions in graphene layers. And they have made a startling discovery.

What did the electron say to the phonon between two layers of graphene?

This might sound like the start of a physics meme with a hilarious punchline to follow. But that’s not the case according to Klaas-Jan Tielrooij. He’s an associate professor at the Department of Applied Physics and Science Education at TU/e and the research lead of the new work published in Science Advances.

“We sought to understand how electrons and phonons ‘talk’ to each other within two twisted graphene layers,” says Tielrooij.

Electrons are the well-known charge and energy carriers associated with electricity, while a phonon is linked to the emergence of vibrations between atoms in an atomic crystal.

“Phonons aren’t particles like electrons though, they’re a quasiparticle. Yet, their interaction with electrons in certain materials and how they affect energy loss in electrons has been a mystery for some time,” notes Tielrooij.

But why would it be interesting to learn more about electron-phonon interactions? “These interactions can have a major effect on the electronic and optoelectronic properties of devices, made from materials like graphene, which we are going to see more of in the future.”

Twistronics: Breakthrough of the Year 2018

Tielrooij and his collaborators, who are based around the world in Spain, Germany, Japan, and the US, decided to study electron-phonon interactions in a very particular case – within two layers of graphene where the layers are ever-so-slightly misaligned.

Graphene is a two-dimensional layer of carbon atoms arranged in a honeycomb lattice that has several impressive properties such as high electrical conductivity, high flexibility, and high thermal conductivity, and it is also nearly transparent.

Back in 2018, the Physics World Breakthrough of the Year award went to Pablo Jarillo-Herrero and colleagues at MIT [Massachusetts Institute of Technology] for their pioneering work on twistronics, where adjacent layers of graphene are rotated very slightly relative to each other to change the electronic properties of the graphene.

Twist and astound!

“Depending on how the layers of graphene are rotated and doped with electrons, contrasting outcomes are possible. For certain dopings, the layers act as an insulator, which prevents the movement of electrons. For other doping, the material behaves as a superconductor – a material with zero resistance that allows the dissipation-less movement of electrons,” says Tielrooij.

Better known as twisted bilayer graphene, these outcomes occur at the so-called magic angle of misalignment, which is just over one degree of rotation. “The misalignment between the layers is tiny, but the possibility for a superconductor or an insulator is an astounding result.”

How electrons lose energy

For their study, Tielrooij and the team wanted to learn more about how electrons lose energy in magic-angle twisted bilayer graphene, or MATBG for short.

To achieve this, they used a material consisting of two sheets of monolayer graphene (each 0.3 nanometers thick), placed on top of each other, and misaligned relative to each other by about one degree.

Then using two optoelectronic measurement techniques, the researchers were able to probe the electron-phonon interactions in detail, and they made some staggering discoveries.

“We observed that the energy vanishes very quickly in the MATBG – it occurs on the picosecond timescale, which is one-millionth of one-millionth of a second!” says Tielrooij.

This observation is much faster than for the case of a single layer of graphene, especially at ultracold temperatures (specifically below -73 degrees Celsius). “At these temperatures, it’s very difficult for electrons to lose energy to phonons, yet it happens in the MATBG.”

Why electrons lose energy

So, why are the electrons losing the energy so quickly through interaction with the phonons? Well, it turns out the researchers have uncovered a whole new physical process.

“The strong electron-phonon interaction is a completely new physical process and involves so-called electron-phonon Umklapp scattering,” adds Hiroaki Ishizuka from Tokyo Institute of Technology in Japan, who developed the theoretical understanding of this process together with Leonid Levitov from Massachusetts Institute of Technology in the US.

Umklapp scattering between phonons is a process that often affects heat transfer in materials, because it enables relatively large amounts of momentum to be transferred between phonons.

“We see the effects of phonon-phonon Umklapp scattering all the time as it affects the ability for (non-metallic) materials at room temperature to conduct heat. Just think of an insulating material on the handle of a pot for example,” says Ishizuka. “However, electron-phonon Umklapp scattering is rare. Here though we have observed for the first time how electrons and phonons interact via Umklapp scattering to dissipate electron energy.”

Challenges solved together

Tielrooij and collaborators may have completed most of the work while he was based in Spain at the Catalan Institute of Nanoscience and Nanotechnology (ICN2), but as Tielrooij notes. “The international collaboration proved pivotal to making this discovery.”

So, how did all the collaborators contribute to the research? Tielrooij: “First, we needed advanced fabrication techniques to make the MATBG samples. But we also needed a deep theoretical understanding of what’s happening in the samples. Added to that, ultrafast optoelectronic measurement setups were required to measure what’s happening in the samples too.”

Tielrooij and the team received the magic-angle twisted samples from Dmitri Efetov’s group at Ludwig-Maximilians-Universität in Munich, who were the first group in Europe able to make such samples and who also performed photomixing measurements, while theoretical work at MIT in the US and at Tokyo Institute of Technology in Japan proved crucial to the success of the research.

At ICN2, Tielrooij and his team members Jake Mehew and Alexander Block used cutting-edge equipment particularly time-resolved photovoltage microscopy to perform their measurements of electron-phonon dynamics in the samples.

The future

So, what does the future look like for these materials then? According to Tielrooij, don’t expect anything too soon.

“As the material is only being studied for a few years, we’re still some way from seeing magic-angle twisted bilayer graphene having an impact on society.”

But there is a great deal to be explored about energy loss in the material.

“Future discoveries could have implications for charge transport dynamics, which could have implications for future ultrafast optoelectronics devices,” says Tielrooij. “In particular, they would be very useful at low temperatures, so that makes the material suitable for space and quantum applications.”

The research from Tielrooij and the international team is a real breakthrough when it comes to how electrons and phonons interact with each other.

But we’ll have to wait a little longer to fully understand the consequences of what the electron said to the phonon in the graphene sandwich.

Illustration showing the control of energy relaxation with twist angle. Image: Authors

Here’s a link to and a citation for the paper,

Ultrafast Umklapp-assisted electron-phonon cooling in magic-angle twisted bilayer graphene by Jake Dudley Mehew, Rafael Luque Merino, Hiroaki Ishizuka, Alexander Block, Jaime Díez Mérida, Andrés Díez Carlón, Kenji Watanabe, Takashi Taniguchi, Leonid S. Levitov, Dmitri K. Efetov, and Klaas-Jan Tielrooij. Science Advances 9 Feb 2024 Vol 10, Issue 6 DOI: 10.1126/sciadv.adj1361

This paper is open access.

D-Wave Systems demonstrates quantum advantage on optimization problems with a 5,000-qubit programmable spin glass

This May 17, 2023 article by Ingrid Fadelli for phys.org describes quantum research performed by D-Wave Systems (a company in Vancouver, Canada) and Boston University (Massachusetts, US), Note: Links have been removed,

Over the past decades, researchers and companies worldwide have been trying to develop increasingly advanced quantum computers. The key objective of their efforts is to create systems that will outperform classical computers on specific tasks, which is also known as realizing “quantum advantage.”

A research team at D-Wave Inc., a quantum computing company, recently created a new quantum computing system that outperforms classical computing systems on optimization problems. This system, introduced in a paper in Nature, is based on a programmable spin glass with 5,000 qubits (the quantum equivalents of bits in classical computing).

“This work validates the original hypothesis behind quantum annealing, coming full circle from some seminal experiments conducted in the 1990s,” Andrew D. King, one of the researchers who carried out the study, told Phys.org.

“These original experiments took chunks of spin-glass alloy and subjected them to varying magnetic fields, and the observations suggested that if we made a programmable quantum spin glass, it could drive down to low-energy states of optimization problems faster than analogous classical algorithms. A Science paper published in 2014 tried to verify this on a D-Wave Two processor, but no speedup was found.”

“This is a ‘full circle’ moment, in the sense that we have verified and extended the hypothesis of the UChicago [University of Chicago] and NEC [Nippon Electric Company] researchers; quantum annealing shows a scaling advantage over simulated thermal annealing,” King said. “Ours is the largest programmable quantum simulation ever performed; reproducing it classically is way beyond the reach of known methods.”

“We have a clear view of quantum effects and very clear evidence, both theoretical and experimental, that the quantum effects are conferring a computational scaling advantage over classical methods,” King said. “We want to highlight the difference between this original definition of quantum advantage and the fact that it is sometimes used as a stand-in term for quantum supremacy, which we have not demonstrated. [emphases mine] Gate-model quantum computers have not shown any capabilities approaching this for optimization, and I personally don’t believe they ever will.”

“For a long time, it was subject for debate whether or not coherent quantum dynamics were playing any role at all in quantum annealing,” King said. “While this controversy has been rebuked by previous works, this new research is the clearest demonstration yet, by far.”

An April 19, 2023 D-Wave Systems news release, which seems to have been the basis for Fadelli’s article, provides more detail in a release that functions as a research announcement and a sales tool, Note: Links have been removed,

D-Wave Quantum Inc. (NYSE: QBTS), a leader in quantum computing systems, software, and services—and the only provider building both annealing and gate-model quantum computers, today published a peer-reviewed milestone paper showing the performance of its 5,000 qubit Advantage™ quantum computer is significantly faster than classical compute on 3D spin glass optimization problems, an intractable class of optimization problems. This paper also represents the largest programmable quantum simulation reported to date.

The paper—a collaboration between scientists from D-Wave and Boston University—entitled “Quantum critical dynamics in a 5,000-qubit programmable spin glass,” was published in the peer-reviewed journal Nature today and is available here. Building upon research conducted on up to 2,000 qubits last September, the study shows that the D-Wave quantum processor can compute coherent quantum dynamics in large-scale optimization problems. This work was done using D-Wave’s commercial-grade annealing-based quantum computer, which is accessible for customers to use today.

With immediate implications to optimization, the findings show that coherent quantum annealing can improve solution quality faster than classical algorithms. The observed speedup matches the theory of coherent quantum annealing and shows​ a direct connection between coherence and the core computational power of quantum annealing.

“This research marks a significant achievement for quantum technology, as it demonstrates a computational advantage over classical approaches for an intractable class of optimization problems,” said Dr. Alan Baratz, CEO of D-Wave. “For those seeking evidence of quantum annealing’s unrivaled performance, this work offers definitive proof.

This work supports D-Wave’s ongoing commitment to relentless scientific innovation and product delivery, as the company continues development on its future annealing and gate model quantum computers. To date, D-Wave has brought to market five generations of quantum computers and launched an experimental prototype of its sixth-generation machine, the Advantage2™ system, in June 2022. The full Advantage2 system is expected to feature 7,000+ qubits, 20-way connectivity and higher coherence to solve even larger and more complex problems. Read more about the research in our Medium post here.

Paper’s Authors and Leading Industry Voices Echo Support

“This is an important advance in the study of quantum phase transitions on quantum annealers. It heralds a revolution in experimental many-body physics and bodes well for practical applications of quantum computing,” said Wojciech Zurek, theoretical physicist at Los Alamos National Laboratory and leading authority on quantum theory. Dr. Zurek is widely renowned for his groundbreaking contribution to our understanding of the early universe as well as condensed matter systems through the discovery of the celebrated Kibble-Zurek mechanism. This mechanism underpins the physics behind the experiment reported in this paper. “The same hardware that has already provided useful experimental proving ground for quantum critical dynamics can be also employed to seek low-energy states that assist in finding solutions to optimization problems.”

“Disordered magnets, such as spin glasses, have long functioned as model systems for testing solvers of complex optimization problems,” said Gabriel Aeppli, professor of physics at ETH Zürich and EPF Lausanne, and head of the Photon Science Division of the Paul Scherrer Institut. Professor Aeppli coauthored the first experimental paper demonstrating advantage of quantum annealing over thermal annealing in reaching ground state of disordered magnets. “This paper gives evidence that the quantum dynamics of a dedicated hardware platform are faster than for known classical algorithms to find the preferred, lowest energy state of a spin glass, and so promises to continue to fuel the further development of quantum annealers for dealing with practical problems.”

“As a physicist who has built my career on computer simulations of quantum systems, it has been amazing to experience first-hand the transformative capabilities of quantum annealing devices,” said Anders Sandvik, professor of physics at Boston University and a coauthor of the paper. “This paper already demonstrates complex quantum dynamics on a scale beyond any classical simulation method, and I’m very excited about the expected enhanced performance of future devices. I believe we are now entering an era when quantum annealing becomes an essential tool for research on complex systems.”

“This work marks a major step towards large-scale quantum simulations of complex materials,” said Hidetoshi Nishimori, Professor, Institute of Innovative Research, Tokyo Institute of Technology and one of the original inventors of quantum annealing. “We can now expect novel physical phenomena to be revealed by quantum simulations using quantum annealing, ultimately leading to the design of materials of significant societal value.”

“This represents some of the most important experimental work ever performed in quantum optimization,” said Dr. Andrew King, director of performance research at D-Wave. “We’ve demonstrated a speedup over simulated annealing, in strong agreement with theory, providing high-quality solutions for large-scale problems. This work shows clear evidence of quantum dynamics in optimization, which we believe paves the way for even more complex problem-solving using quantum annealing in the future. The work exhibits a programmable realization of lab experiments that originally motivated quantum annealing 25 years ago.”

“Not only is this the largest demonstration of quantum simulation to date, but it also provides the first experimental evidence, backed by theory, that coherent quantum dynamics can accelerate the attainment of better solutions in quantum annealing,” said Mohammad Amin, fellow, quantum algorithms and systems, at D-Wave. “The observed speedup can be attributed to complex critical dynamics during quantum phase transition, which cannot be replicated by classical annealing algorithms, and the agreement between theory and experiment is remarkable. We believe these findings have significant implications for quantum optimization, with practical applications in addressing real-world problems.”

About D-Wave Quantum Inc.

D-Wave is a leader in the development and delivery of quantum computing systems, software, and services, and is the world’s first commercial supplier of quantum computers—and the only company building both annealing quantum computers and gate-model quantum computers. Our mission is to unlock the power of quantum computing today to benefit business and society. We do this by delivering customer value with practical quantum applications for problems as diverse as logistics, artificial intelligence, materials sciences, drug discovery, scheduling, cybersecurity, fault detection, and financial modeling. D-Wave’s technology is being used by some of the world’s most advanced organizations, including Volkswagen, Mastercard, Deloitte, Davidson Technologies, ArcelorMittal, Siemens Healthineers, Unisys, NEC Corporation, Pattison Food Group Ltd., DENSO, Lockheed Martin, Forschungszentrum Jülich, University of Southern California, and Los Alamos National Laboratory.

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, which statements are based on beliefs and assumptions and on information currently available. In some cases, you can identify forward-looking statements by the following words: “may,” “will,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “anticipate,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “ongoing,” or the negative of these terms or other comparable terminology, although not all forward-looking statements contain these words. These statements involve risks, uncertainties, and other factors that may cause actual results, levels of activity, performance, or achievements to be materially different from the information expressed or implied by these forward-looking statements. We caution you that these statements are based on a combination of facts and factors currently known by us and our projections of the future, which are subject to a number of risks. Forward-looking statements in this press release include, but are not limited to, statements regarding the impact of the results of this study; the company’s Advantage2™ experimental prototype; and the potential for future problem-solving using quantum annealing. We cannot assure you that the forward-looking statements in this press release will prove to be accurate. These forward-looking statements are subject to a number of risks and uncertainties, including, among others, various factors beyond management’s control, including general economic conditions and other risks, our ability to expand our customer base and the customer adoption of our solutions, and the uncertainties and factors set forth in the sections entitled “Risk Factors” and “Cautionary Note Regarding Forward-Looking Statements” in D-Wave Quantum Inc.’s Form S-4 Registration Statement, as amended, previously filed with the Securities and Exchange Commission, as well as factors associated with companies, such as D-Wave, that are engaged in the business of quantum computing, including anticipated trends, growth rates, and challenges in those businesses and in the markets in which they operate; the outcome of any legal proceedings that may be instituted against us; risks related to the performance of our business and the timing of expected business or financial milestones; unanticipated technological or project development challenges, including with respect to the cost and or timing thereof; the performance of the our products; the effects of competition on our business; the risk that we will need to raise additional capital to execute our business plan, which may not be available on acceptable terms or at all; the risk that we may never achieve or sustain profitability; the risk that we are unable to secure or protect our intellectual property; volatility in the price of our securities; and the risk that our securities will not maintain the listing on the NYSE. Furthermore, if the forward-looking statements contained in this press release prove to be inaccurate, the inaccuracy may be material. In addition, you are cautioned that past performance may not be indicative of future results. In light of the significant uncertainties in these forward-looking statements, you should not place undue reliance on these statements in making an investment decision or regard these statements as a representation or warranty by any person we will achieve our objectives and plans in any specified time frame, or at all. The forward-looking statements in this press release represent our views as of the date of this press release. We anticipate that subsequent events and developments will cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we have no current intention of doing so except to the extent required by applicable law. You should, therefore, not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this press release.

Here’s a link to and a citation for the paper,

Quantum critical dynamics in a 5,000-qubit programmable spin glass by Andrew D. King, Jack Raymond, Trevor Lanting, Richard Harris, Alex Zucca, Fabio Altomare, Andrew J. Berkley, Kelly Boothby, Sara Ejtemaee, Colin Enderud, Emile Hoskinson, Shuiyuan Huang, Eric Ladizinsky, Allison J. R. MacDonald, Gaelen Marsden, Reza Molavi, Travis Oh, Gabriel Poulin-Lamarre, Mauricio Reis, Chris Rich, Yuki Sato, Nicholas Tsai, Mark Volkmann, Jed D. Whittaker, Jason Yao, Anders W. Sandvik & Mohammad H. Amin. Nature volume 617, pages 61–66 (2023) DOI: https://doi.org/10.1038/s41586-023-05867-2 Published: 19 April 2023 Issue Date: 04 May 2023

This paper is behind a paywall but there is an open access version on the arxiv website which means that it has had some peer review but may differ from the version in Nature.

Physics in James Joyce’s Ulysses and physics amongst the penguins

So James Joyce included some physics in his novel, Ulysses (serialized in The Little Review from March 1918 to December1920 and published as a novel in February 1922)?

That’s not the only surprise. Apparently, penguins perform some interesting feats from a physics perspective. I have two stories about penguin physics with the latest research being published in June 2023.

Let’s start with literature.

James Joyce, Ulysses, and 19th century physics

This article came to my attention in April 2023 but the material is from 2021/22. Thankfully, since it’s a literature topic, timing doesn’t matter quite as much as it does for other topics. From a December 22, 2021 American Institute of Physics news release highlights an intriguing article in The Physics Teacher,

James Joyce’s book “Ulysses” is widely considered a 20th-century literary masterpiece. It also contains a surprising amount of 19th-century classical physics, according to Harry Manos, faculty member at Los Angeles City College.

“Ulysses” chronicles the ordinary life of the protagonist Leopold Bloom over a single day in 1904. In The Physics Teacher, by AIP Publishing, Manos reveals several connections that have not been analyzed before in the Joycean literature between classic physics prevalent during that time and various passages of the book.

“‘Ulysses’ exemplifies what physics students and teachers should realize — namely, physics and literature are not mutually exclusive,” Manos said.

Manos shows how Joyce uses the optics of concave and convex mirrors to metaphorically parallel “Ulysses” with Homer’s “Odyssey,” and how Joyce uses physics to show Bloom’s strengths and weaknesses in science.

Here’s a link to and a citation for the paper,

Physics in James Joyce’s Ulysses by Harry Manos. The Physics Teacher 60, 6–10 (2022) DOI: https://doi.org/10.1119/5.0028832 Published online: January 1, 2022

This paper is behind a paywall but there is a freely available abstract

Ulysses by James Joyce (1882–1941) has a surprising amount of 19th-century, classical physics. The physics community is familiar with the name James Joyce mainly through the word “quark” (onomatopoeic for the sound of a duck or seagull), which Murray Gell-Mann (1929-2019 – Physics Nobel Prize 1969) sourced from Joyce’s Finnegan’s Wake. Ulysses, however, was ranked number one in 1998 on the Modern Library “100 Best Novels” list and is, in whole or in part, in the literature curriculum in university English departments worldwide. The fact that Ulysses contains so much classical physics should not be surprising. Joyce’s friend Eugene Jolas observed: “the range of subjects he [Joyce] enjoyed discussing was a wide one … [including] certain sciences, particularly physics, geometry, and mathematics.” Knowing physics can enhance everyone’s understanding of this novel and enrich its entertainment value. Ulysses exemplifies what physics students (science and non-science majors) and physics teachers should realize, namely, physics and literature are not mutually exclusive.

In addition to the December 22, 2021 American Institute of Physics news release which provides some detail about the physics in Ulysses, there’s Jennifer Ouellette’s April 2, 2023 article for Ars Technica where in addition to the material in the news release, she adds some intriguing information, Note: Links have been removed,

In Chapter 15 (“Circe”), one of the characters says, “You can call me up by sunphone any old time”—a phrase that also appears in Joyce’s handwritten notes for the chapter. While Manos was unable to trace a specific source for this term, there was a similar device that had been invented some 20 years earlier: Alexander Graham Bell’s photophone, co-invented with his assistant Charles Sumner Tainter.

Unlike the telephone, which relies on electricity, the photophone transmitted sound on a beam of light. Bell’s voice was projected through the instrument to a mirror, causing similar vibrations in the mirror. When he directed sunlight into the mirror, it captured and projected the mirror’s vibrations via reflection, which were then transformed back into sound at the receiving end of the projection. Bell’s device never found immediate application, but it’s arguably the progenitor to modern fiber-optic telecommunications.

There are several other instances of physics (both correct and incorrect/outdated) mentioned in Ulysses, per Manos, including Bloom misunderstanding the science of X-rays; his confusion over parallax; trying to figure out the source of buoyancy in the Dead Sea; ruminating on Archimedes’ “burning glass”; seeing rainbow colors in a water spray; and pondering why he hears the ocean when he places a seashell to his ear. Manos believes introducing literature like Ulysses into physics courses could be a boon for non-majors, as well as encouraging physics and engineering students to learn more about literature.

In fact, Manos notes that an earlier 1995 paper introduced a handy introductory physics problem involving distance, velocity, and time. Ulysses opens with Stephen Dedalus and his roommate, Buck Mulligan, standing at the Martello tower overlooking a bay at Sandy Cove. …

Now onto …

Penguin physics

Two stories, two research teams, and six months separate their papers.

A February 7, 2023 news item on phys.org features work from a team of Japanese scientists studying how penguins turn in the water, Note: A link has been removed,

Penguins constitute a fascinating family of flightless birds, that although somewhat clumsy on land, are extremely talented swimmers. Their incredible maneuverability in water has captivated biologists for decades, with the first hydrodynamic studies on their swimming dating back to the 1970s.

Although a rare few studies have clarified some of the physics behind penguins’ dexterity, most of them have focused on forward swimming rather than turning. While one may argue that existing studies on the turning mechanisms of flying birds could shed some light on this topic, water is 800 hundred times denser than air, and thus the turning mechanisms employed are presumably very different between these media.

In an effort to bridge this knowledge gap, a pair of Japanese scientists from Tokyo Institute of Technology (Tokyo Tech), including Associate Professor Hiroto Tanaka, recently conducted a study. The main goal of this work, which was published in Journal of Experimental Biology, was to gain a better understanding of the three dimensional (3D) kinematics and hydrodynamic forces that enable penguins to turn underwater.

Penguin Physics: Understanding the Mechanisms of Underwater Turning Maneuvers in Penguins
Credit: Tokyo Institute of Technology

A February 8, 2023 Tokyo Institute of Technology (Tokyo Tech) press release, which originated the news item, describes the research in more technical detail,

The researchers recorded two sessions of gentoo penguins (Pygoscelis papua) free swimming in a large water tank at Nagasaki Penguin Aquarium, Japan, using a dozen or more underwater cameras. Then, thanks to a technique called 3D direct linear transformation, they were able to integrate data from all the footage and conduct detailed 3D motion analyses by tracking various points on the penguins’ bodies and wings.

Armed with these data, the researchers then established a mathematical 3D body model of the penguins. This model covered the orientation and angles of the body, the different positions and motions of the wings during each stroke, the associated kinematic parameters and hydrodynamic forces, and various turning metrics. Through statistical analyses and comparisons with the experimental data, the researchers validated the model and gained insight into the role of the wings and other body movements during turning.

The main findings of the study were related to how penguins generate centripetal force to assist their turns. They achieve this, in part, is by maintaining outward banking, which means that they tilt their bodies such that their belly faces inward. In powered turns—those in which the penguin flaps its wings—the majority of changes in direction occur during the upstroke, whereas the forward thrust occurs during the downstroke. In addition, it turns out that penguins flap their wings with a certain asymmetry during powered turns. “We found contralateral differences in wing motion; the wing on the inside of the turn becomes more elevated during the upstroke than the other,” explains Assoc. Prof. Tanaka, “Quasi-steady calculations of wing forces confirmed that this asymmetry in wing motion with the outward banking contributes to the generation of centripetal force during the upstroke. In the following downstroke, the inside wing generates thrust and counter yaw torque to brake the turning.”

Overall, these findings contribute to a greater understanding of how penguins turn when swimming, which is relevant from both biological and engineering standpoints. However, Assoc. Prof. Tanaka remarks that these findings bring but one piece to the puzzle: “The mechanisms of various other maneuvers in penguins, such as rapid acceleration, pitch up and down, and jumping out of the water, are still unknown. Our study serves as the basis for further understanding of more complex maneuvers.”

Let us hope future research helps fully clarify how penguins achieve their mesmerizing aquatic prowess!

Here’s a link to and a citation for the paper,

Kinematic and hydrodynamic analyses of turning manoeuvres in penguins: body banking and wing upstroke generate centripetal force by Natsuki Harada and Hiroto Tanaka. J Exp Biol (2022) 225 (24): jeb244124. DOI: https://doi.org/10.1242/jeb.244124 Published online December 22, 2022

This paper is open access.

Penguins are the fastest swimming birds and this team published a paper about their propulsion six months after the ‘turning’ team according to a June 20, 2023 news item on phys.org,

Penguins aren’t just cute: they’re also speedy. Gentoo penguins are the fastest swimming birds in the world, and that ability comes from their unique and sophisticated wings.

Researchers from the University of Chinese Academy of Sciences, Chinese Academy of Sciences, and King Mongkut’s Institute of Technology Ladkrabang [KMITL or KMIT Ladkrabang; Thailand] developed a model to explore the forces and flow structures created by penguin wings underwater. They determined that wing feathering is the main factor for generating thrust. Their findings have been published in the journal Physics of Fluids.

An American Institute of Physics June 20, 2022 news release (also on EurekAlert), which originated the news item, provides further explanation of how penguins are able to achieve their swimming speed,

Penguin wings, aka flippers, bear some resemblance to airplane wings covered with scaly feathers. To maximize efficiency underwater instead of in the air, penguin wings are shorter and flatter than those of flying birds.

The animals can adjust swimming posture by active wing feathering (changing the angle of their wings to reduce resistance), pitching, and flapping. Their dense, short feathers can also lock air between the skin and water to reduce friction and turbulence.

“Penguins’ superior swimming ability to start/brake, accelerate/decelerate, and turn swiftly is due to their freely waving wings. They allow penguins to propel and maneuver in the water and maintain balance on land,” said author Prasert Prapamonthon. “Our research team is always curious about sophisticated creatures in nature that would be beneficial to mankind.”

The hydrodynamic model takes in information about the flapping and feathering of the wings, including amplitude, frequency, and direction, and the fluid parameters, such as velocity and viscosity. Using the immersed boundary method, it solves for the motion of the wing and the thrust, lift, and lateral forces.

To establish the movement of wings across species, researchers use the ratio of wing flapping speed to forward speed. This value avoids any differences between air and water. Additionally, the authors define an angle of thrust, determined by the angle of the wings. Both of these parameters have a significant impact on the penguin’s thrust.

“We proposed the concept of angle of thrust, which explains why finned wings generate thrust: Thrust is primarily determined by the angle of attack and the relative angle of the wings to the forward direction,” said Prapamonthon. “The angle of thrust is an important concept in studying the mechanism of thrust generated by flapping motion and will be useful for designing mechanical wing motion.”

These findings can guide the design of aquatic vehicles by quickly estimating propulsion performance without high experimental or computational costs.

In the future, the team plans to examine a more realistic 3D penguin model. They will incorporate different wing properties and motion, such as starting, braking, turning, and jumping in and out of water.

Here’s a link to and a citation for the paper,

Hydrodynamic performance of a penguin wing: Effect of feathering and flapping by Hao Zhanzhou (郝占宙), Yin Bo (银波), Prasert Prapamonthon, Yang Guowei (杨国). Physics of Fluids 35 (6), 061907 (2023) DOI: https://doi.org/10.1063/5.0147776 Published online: June 20, 2023

This paper is open access.

Exotic magnetism: a quantum simulation from D-Wave Sytems

Vancouver (Canada) area company, D-Wave Systems is trumpeting itself (with good reason) again. This 2021 ‘milestone’ achievement builds on work from 2018 (see my August 23, 2018 posting for the earlier work). For me, the big excitement was finding the best explanation for quantum annealing and D-Wave’s quantum computers that I’ve seen yet (that explanation and a link to more is at the end of this posting).

A February 18, 2021 news item on phys.org announces the latest achievement,

D-Wave Systems Inc. today [February 18, 2021] published a milestone study in collaboration with scientists at Google, demonstrating a computational performance advantage, increasing with both simulation size and problem hardness, to over 3 million times that of corresponding classical methods. Notably, this work was achieved on a practical application with real-world implications, simulating the topological phenomena behind the 2016 Nobel Prize in Physics. This performance advantage, exhibited in a complex quantum simulation of materials, is a meaningful step in the journey toward applications advantage in quantum computing.

A February 18, 2021 D-Wave Systems press release (also on EurekAlert), which originated the news item, describes the work in more detail,

The work by scientists at D-Wave and Google also demonstrates that quantum effects can be harnessed to provide a computational advantage in D-Wave processors, at problem scale that requires thousands of qubits. Recent experiments performed on multiple D-Wave processors represent by far the largest quantum simulations carried out by existing quantum computers to date.

The paper, entitled “Scaling advantage over path-integral Monte Carlo in quantum simulation of geometrically frustrated magnets”, was published in the journal Nature Communications (DOI 10.1038/s41467-021-20901-5, February 18, 2021). D-Wave researchers programmed the D-Wave 2000Q™ system to model a two-dimensional frustrated quantum magnet using artificial spins. The behavior of the magnet was described by the Nobel-prize winning work of theoretical physicists Vadim Berezinskii, J. Michael Kosterlitz and David Thouless. They predicted a new state of matter in the 1970s characterized by nontrivial topological properties. This new research is a continuation of previous breakthrough work published by D-Wave’s team in a 2018 Nature paper entitled “Observation of topological phenomena in a programmable lattice of 1,800 qubits” (Vol. 560, Issue 7719, August 22, 2018). In this latest paper, researchers from D-Wave, alongside contributors from Google, utilize D-Wave’s lower noise processor to achieve superior performance and glean insights into the dynamics of the processor never observed before.

“This work is the clearest evidence yet that quantum effects provide a computational advantage in D-Wave processors,” said Dr. Andrew King, principal investigator for this work at D-Wave. “Tying the magnet up into a topological knot and watching it escape has given us the first detailed look at dynamics that are normally too fast to observe. What we see is a huge benefit in absolute terms, with the scaling advantage in temperature and size that we would hope for. This simulation is a real problem that scientists have already attacked using the algorithms we compared against, marking a significant milestone and an important foundation for future development. This wouldn’t have been possible today without D-Wave’s lower noise processor.”

“The search for quantum advantage in computations is becoming increasingly lively because there are special problems where genuine progress is being made. These problems may appear somewhat contrived even to physicists, but in this paper from a collaboration between D-Wave Systems, Google, and Simon Fraser University [SFU], it appears that there is an advantage for quantum annealing using a special purpose processor over classical simulations for the more ‘practical’ problem of finding the equilibrium state of a particular quantum magnet,” said Prof. Dr. Gabriel Aeppli, professor of physics at ETH Zürich and EPF Lausanne, and head of the Photon Science Division of the Paul Scherrer Institute. “This comes as a surprise given the belief of many that quantum annealing has no intrinsic advantage over path integral Monte Carlo programs implemented on classical processors.”

“Nascent quantum technologies mature into practical tools only when they leave classical counterparts in the dust in solving real-world problems,” said Hidetoshi Nishimori, Professor, Institute of Innovative Research, Tokyo Institute of Technology. “A key step in this direction has been achieved in this paper by providing clear evidence of a scaling advantage of the quantum annealer over an impregnable classical computing competitor in simulating dynamical properties of a complex material. I send sincere applause to the team.”

“Successfully demonstrating such complex phenomena is, on its own, further proof of the programmability and flexibility of D-Wave’s quantum computer,” said D-Wave CEO Alan Baratz. “But perhaps even more important is the fact that this was not demonstrated on a synthetic or ‘trick’ problem. This was achieved on a real problem in physics against an industry-standard tool for simulation–a demonstration of the practical value of the D-Wave processor. We must always be doing two things: furthering the science and increasing the performance of our systems and technologies to help customers develop applications with real-world business value. This kind of scientific breakthrough from our team is in line with that mission and speaks to the emerging value that it’s possible to derive from quantum computing today.”

The scientific achievements presented in Nature Communications further underpin D-Wave’s ongoing work with world-class customers to develop over 250 early quantum computing applications, with a number piloting in production applications, in diverse industries such as manufacturing, logistics, pharmaceutical, life sciences, retail and financial services. In September 2020, D-Wave brought its next-generation Advantage™ quantum system to market via the Leap™ quantum cloud service. The system includes more than 5,000 qubits and 15-way qubit connectivity, as well as an expanded hybrid solver service capable of running business problems with up to one million variables. The combination of Advantage’s computing power and scale with the hybrid solver service gives businesses the ability to run performant, real-world quantum applications for the first time.

That last paragraph seems more sales pitch than research oriented. It’s not unexpected in a company’s press release but I was surprised that the editors at EurekAlert didn’t remove it.

Here’s a link to and a citation for the latest paper,

Scaling advantage over path-integral Monte Carlo in quantum simulation of geometrically frustrated magnets by Andrew D. King, Jack Raymond, Trevor Lanting, Sergei V. Isakov, Masoud Mohseni, Gabriel Poulin-Lamarre, Sara Ejtemaee, William Bernoudy, Isil Ozfidan, Anatoly Yu. Smirnov, Mauricio Reis, Fabio Altomare, Michael Babcock, Catia Baron, Andrew J. Berkley, Kelly Boothby, Paul I. Bunyk, Holly Christiani, Colin Enderud, Bram Evert, Richard Harris, Emile Hoskinson, Shuiyuan Huang, Kais Jooya, Ali Khodabandelou, Nicolas Ladizinsky, Ryan Li, P. Aaron Lott, Allison J. R. MacDonald, Danica Marsden, Gaelen Marsden, Teresa Medina, Reza Molavi, Richard Neufeld, Mana Norouzpour, Travis Oh, Igor Pavlov, Ilya Perminov, Thomas Prescott, Chris Rich, Yuki Sato, Benjamin Sheldan, George Sterling, Loren J. Swenson, Nicholas Tsai, Mark H. Volkmann, Jed D. Whittaker, Warren Wilkinson, Jason Yao, Hartmut Neven, Jeremy P. Hilton, Eric Ladizinsky, Mark W. Johnson, Mohammad H. Amin. Nature Communications volume 12, Article number: 1113 (2021) DOI: https://doi.org/10.1038/s41467-021-20901-5 Published: 18 February 2021

This paper is open access.

Quantum annealing and more

Dr. Andrew King, one of the D-Wave researchers, has written a February 18, 2021 article on Medium explaining some of the work. I’ve excerpted one of King’s points,

Insight #1: We observed what actually goes on under the hood in the processor for the first time

Quantum annealing — the approach adopted by D-Wave from the beginning — involves setting up a simple but purely quantum initial state, and gradually reducing the “quantumness” until the system is purely classical. This takes on the order of a microsecond. If you do it right, the classical system represents a hard (NP-complete) computational problem, and the state has evolved to an optimal, or at least near-optimal, solution to that problem.

What happens at the beginning and end of the computation are about as simple as quantum computing gets. But the action in the middle is hard to get a handle on, both theoretically and experimentally. That’s one reason these experiments are so important: they provide high-fidelity measurements of the physical processes at the core of quantum annealing. Our 2018 Nature article introduced the same simulation, but without measuring computation time. To benchmark the experiment this time around, we needed lower-noise hardware (in this case, we used the D-Wave 2000Q lower noise quantum computer), and we needed, strangely, to slow the simulation down. Since the quantum simulation happens so fast, we actually had to make things harder. And we had to find a way to slow down both quantum and classical simulation in an equitable way. The solution? Topological obstruction.

If you have time and the inclination, I encourage you to read King’s piece.

Put a ring on it: preventing clumps of gold nanoparticles

Caption: A comparison of how linear PEG (left) and cyclic PEG (right) attach to a gold nanoparticle Credit: Yubo Wang, Takuya Yamamoto

A January 20, 2021 news item on phys.org focuses on work designed to stop gold nanoparticles from clumping together (Note: A link has been removed),

Hokkaido University scientists have found a way to prevent gold nanoparticles from clumping, which could help towards their use as an anti-cancer therapy.

Attaching ring-shaped synthetic compounds to gold nanoparticles helps them retain their essential light-absorbing properties, Hokkaido University researchers report in the journal Nature Communications.

A January 20, 2021 Hokkaido University press release (also on EurekAlert but published Jan. 21, 2020), which originated the news item, elaborates on the work,

Metal nanoparticles have unique light-absorbing properties, making them interesting for a wide range of optical, electronic and biomedical applications. For example, if delivered to a tumour, they could react with applied light to kill cancerous tissue. A problem with this approach, though, is that they easily clump together in solution, losing their ability to absorb light. This clumping happens in response to a variety of factors, including temperature, salt concentration and acidity.

Scientists have been trying to find ways to ensure nanoparticles stay dispersed in their target environments. Covering them with polyethylene glycol, otherwise known as PEG, has been relatively successful at this in the case of gold nanoparticles. PEG is biocompatible and can prevent gold surfaces from clumping together in the laboratory and in living organisms, but improvements are still needed.

Applied chemist Takuya Yamamoto and colleagues at Hokkaido University, The University of Tokyo, and Tokyo Institute of Technology found that mixing gold nanoparticles with ring-shaped PEG, rather than the normally linear PEG, significantly improved dispersion. The ‘cyclic-PEG’ (c-PEG) attaches to the surfaces of the nanoparticles without forming chemical bonds with them, a process called physisorption. The coated nanoparticles remained dispersed when frozen, freeze-dried and heated.

The team tested the c-PEG-covered gold nanoparticles in mice and found that they cleared slowly from the blood and accumulated better in tumours compared to gold nanoparticles coated with linear PEG. However, accumulation was lower than desired levels, so the researchers recommend further investigations to fine-tune the nanoparticles for this purpose.

Associate Professor Takuya Yamamoto is part of the Laboratory of Chemistry of Molecular Assemblies at Hokkaido University, where he studies the properties and applications of various cyclic chemical compounds.

Here’s a link to and a citation for the paper,

Enhanced dispersion stability of gold nanoparticles by the physisorption of cyclic poly(ethylene glycol) by Yubo Wang, Jose Enrico Q. Quinsaat, Tomoko Ono, Masatoshi Maeki, Manabu Tokeshi, Takuya Isono, Kenji Tajima, Toshifumi Satoh, Shin-ichiro Sato, Yutaka Miura & Takuya Yamamoto. Nature Communications volume 11, Article number: 6089 (2020) DOI: https://doi.org/10.1038/s41467-020-19947-8 Published: 30 November 2020

This paper is open access.

A deep look at atomic switches

A July 19, 2019 news item on phys.org describes research that may result in a substantive change for information technology,

A team of researchers from Tokyo Institute of Technology has gained unprecedented insight into the inner workings of an atomic switch. By investigating the composition of the tiny metal ‘bridge’ that forms inside the switch, their findings may spur the design of atomic switches with improved performance.

A July 22, 2019 Tokyo Institute of Technology press release (also on EurekAlert but published July 19, 2019), which originated the news item, explains how this research could have such an important impact,

Atomic switches are hailed as the tiniest of electrochemical switches that could change the face of information technology. Due to their nanoscale dimensions and low power consumption, they hold promise for integration into next-generation circuits that could drive the development of artificial intelligence (AI) and Internet of Things (IoT) devices.

Although various designs have emerged, one intriguing question concerns the nature of the metallic filament, or bridge, that is key to the operation of the switch. The bridge forms inside a metal sulfide layer sandwiched between two electrodes [see figure below], and is controlled by applying a voltage that induces an electrochemical reaction. The formation and annihilation of this bridge determines whether the switch is on or off.

Now, a research group including Akira Aiba and Manabu Kiguchi and colleagues at Tokyo Institute of Technology’s Department of Chemistry has found a useful way to examine precisely what the bridge is composed of.

By cooling the atomic switch enough so as to be able to investigate the bridge using a low-temperature measurement technique called point contact spectroscopy (PCS) [2], their study revealed that the bridge is made up of metal atoms from both the electrode and the metal sulfide layer. This surprising finding controverts the prevailing notion that the bridge derives from the electrode only, Kiguchi explains.

The team compared atomic switches with different combinations of electrodes (Pt and Ag, or Pt and Cu) and metal sulfide layers (Cu2S and Ag2S). In both cases, they found that the bridge is mainly composed of Ag.

The reason behind the dominance of Ag in the bridge is likely due to “the higher mobility of Ag ions compared to Cu ions”, the researchers say in their paper published in ACS Applied Materials & Interfaces.

They conclude that “it would be better to use metals with low mobility” for designing atomic switches with higher stability.

Much remains to be explored in the advancement of atomic switch technologies, and the team is continuing to investigate which combination of elements would be the most effective in improving performance.

###

Technical terms
[1] Atomic switch: The idea behind an atomic switch — one that can be controlled by the motion of a single atom — was introduced by Donald Eigler and colleagues at the IBM Almaden Research Center in 1991. Interest has since focused on how to realize and harness the potential of such extremely small switches for use in logic circuits and memory devices. Over the past two decades, researchers in Japan have taken a world-leading role in the development of atomic switch technologies.
[2] Point contact spectroscopy: A method of measuring the properties or excitations of single atoms at low temperature.

Caption: The ‘bridge’ that forms within the metal sulfide layer, connecting two metal electrodes, results in the atomic switch being turned on. Credit: Manabu Kiguchi

Here’s a link to and a citation for the paper,

Investigation of Ag and Cu Filament Formation Inside the Metal Sulfide Layer of an Atomic Switch Based on Point-Contact Spectroscopy by A. Aiba, R. Koizumi, T. Tsuruoka, K. Terabe, K. Tsukagoshi, S. Kaneko, S. Fujii, T. Nishino, M. Kiguchi. ACS Appl. Mater. Interfaces 2019 XXXXXXXXXX-XXX DOI: https://doi.org/10.1021/acsami.9b05523 Publication Date:July 5, 2019 Copyright © 2019 American Chemical Society

This paper is behind a paywall.

For anyone who might need a bit of a refresher for the chemical elements, Pt is platinum, Ag is silver, and Cu is copper. So, with regard to the metal sulfide layers Cu2S is copper sulfide and Ag2S is silver sulfide.

Periodic table of nanomaterials

This charming illustration is the only pictorial representation i’ve seen for Kyoto University’s (Japan) proposed periodic table of nanomaterials, (By the way, 2019 is UNESCO’s [United Nations Educational, Scientific and Cultural Organization] International Year of the Periodic Table of Elements, an event recognizing the table’s 150th anniversary. See my January 8, 2019 posting for information about more events.)

Caption: Molecules interact and align with each other as they self-assemble. This new simulation enables to find what molecules best interact with each other to build nanomaterials, such as materials that work as a nano electrical wire.
Credit Illustration by Izumi Mindy Takamiya

A July 23, 2018 news item on Nanowerk announces the new periodic table (Note: A link has been removed),

The approach was developed by Daniel Packwood of Kyoto University’s Institute for Integrated Cell-Material Sciences (iCeMS) and Taro Hitosugi of the Tokyo Institute of Technology (Nature Communications, “Materials informatics for self-assembly of functionalized organic precursors on metal surfaces”). It involves connecting the chemical properties of molecules with the nanostructures that form as a result of their interaction. A machine learning technique generates data that is then used to develop a diagram that categorizes different molecules according to the nano-sized shapes they form.

This approach could help materials scientists identify the appropriate molecules to use in order to synthesize target nanomaterials.

A July 23, 2018 Kyoto University press release on EurekAlert, which originated the news item, explains further about the computer simulations run by the scientists in pursuit of their specialized periodic table,

Fabricating nanomaterials using a bottom-up approach requires finding ‘precursor molecules’ that interact and align correctly with each other as they self-assemble. But it’s been a major challenge knowing how precursor molecules will interact and what shapes they will form.

Bottom-up fabrication of graphene nanoribbons is receiving much attention due to their potential use in electronics, tissue engineering, construction, and bio-imaging. One way to synthesise them is by using bianthracene precursor molecules that have bromine ‘functional’ groups attached to them. The bromine groups interact with a copper substrate to form nano-sized chains. When these chains are heated, they turn into graphene nanoribbons.

Packwood and Hitosugi tested their simulator using this method for building graphene nanoribbons.

Data was input into the model about the chemical properties of a variety of molecules that can be attached to bianthracene to ‘functionalize’ it and facilitate its interaction with copper. The data went through a series of processes that ultimately led to the formation of a ‘dendrogram’.

This showed that attaching hydrogen molecules to bianthracene led to the development of strong one-dimensional nano-chains. Fluorine, bromine, chlorine, amidogen, and vinyl functional groups led to the formation of moderately strong nano-chains. Trifluoromethyl and methyl functional groups led to the formation of weak one-dimensional islands of molecules, and hydroxide and aldehyde groups led to the formation of strong two-dimensional tile-shaped islands.

The information produced in the dendogram changed based on the temperature data provided. The above categories apply when the interactions are conducted at -73°C. The results changed with warmer temperatures. The researchers recommend applying the data at low temperatures where the effect of the functional groups’ chemical properties on nano-shapes are most clear.

The technique can be applied to other substrates and precursor molecules. The researchers describe their method as analogous to the periodic table of chemical elements, which groups atoms based on how they bond to each other. “However, in order to truly prove that the dendrograms or other informatics-based approaches can be as valuable to materials science as the periodic table, we must incorporate them in a real bottom-up nanomaterial fabrication experiment,” the researchers conclude in their study published in the journal xxx. “We are currently pursuing this direction in our laboratories.”

Here’s a link to and a citation for the paper,

Materials informatics for self-assembly of functionalized organic precursors on metal surfaces by Daniel M. Packwood & Taro Hitosugi. Nature Communicationsvolume 9, Article number: 2469 (2018)DOI: https://doi.org/10.1038/s41467-018-04940-z Published 25 June 2018

This paper is open access.

Nano-saturn

It’s a bit of a stretch but I really appreciate how the nanoscale (specifically a fullerene) is being paired with the second largest planet (the largest is Jupiter) in our solar system. (See Nola Taylor Redd’s November 14, 2012 article on space.com for more about the planet Saturn.)

From a June 8, 2018 news item on ScienceDaily,

Saturn is the second largest planet in our solar system and has a characteristic ring. Japanese researchers have now synthesized a molecular “nano-Saturn.” As the scientists report in the journal Angewandte Chemie, it consists of a spherical C(60) fullerene as the planet and a flat macrocycle made of six anthracene units as the ring. The structure is confirmed by spectroscopic and X-ray analyses.

A June 8, 2018  Wiley Publications press release (also on EurekAlert), which originated the news item, fills in some details,

Nano-Saturn systems with a spherical molecule and a macrocyclic ring have been a fascinating structural motif for researchers. The ring must have a rigid, circular form, and must hold the molecular sphere firmly in its midst. Fullerenes are ideal candidates for the nano-sphere. They are made of carbon atoms linked into a network of rings that form a hollow sphere. The most famous fullerene, C60, consists of 60 carbon atoms arranged into 5- and 6-membered rings like the leather patches of a classic soccer ball. The electrons in their double bonds, knows as the π-electrons, are in a kind of “electron cloud”, able to freely move about and have binding interactions with other molecules, such as a macrocycle that also has a “cloud” of π-electrons. The attractive interactions between the electron clouds allow fullerenes to lodge in the cavities of such macrocycles.

A series of such complexes has previously been synthesized. Because of the positions of the electron clouds around the macrocycles, it was previously only possible to make rings that surround the fullerene like a belt or a tire. The ring around Saturn, however, is not like a “belt” or “tire”, it is a very flat disc. Researchers working at the Tokyo Institute of Technology and Okayama University of Science (Japan) wanted to properly imitate this at nanoscale.

Their success resulted from a different type of bonding between the “nano-planet” and its “nano-ring”. Instead of using the attraction between the π-electron clouds of the fullerene and macrocycle, the team working with Shinji Toyota used the weak attractive interactions between the π-electron cloud of the fullerene and non- π-electron of the carbon-hydrogen groups of the macrocycle.

To construct their “Saturn ring”, the researchers chose to use anthracene units, molecules made of three aromatic six-membered carbon rings linked along their edges. They linked six of these units into a macrocycle whose cavity was the perfect size and shape for a C60 fullerene. Eighteen hydrogen atoms of the macrocycle project into the middle of the cavity. In total, their interactions with the fullerene are enough to give the complex enough stability, as shown by computer simulations. By using X-ray analysis and NMR spectroscopy, the team was able to prove experimentally that they had produced Saturn-shaped complexes.

Here’s an illustration of the ‘nano-saturn’,

Courtesy: Wiley Publications

Here’s a link to and a citation for the paper,

Nano‐Saturn: Experimental Evidence of Complex Formation of an Anthracene Cyclic Ring with C60 by Yuta Yamamoto, Dr. Eiji Tsurumaki, Prof. Dr. Kan Wakamatsu, Prof. Dr. Shinji Toyota. Angewandte Chemie https://doi.org/10.1002/anie.201804430 First published: 30 May 2018

This paper is behind a paywall.