Tag Archives: ETH Zurich

A biochemical means of protecting passwords and anti-counterfeiting solution for art and other precious goods

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I guess you could say my passwords are as precious to me as a piece.of art is to some people.

DNA can be used to confirm the authenticity of valuable art prints. (AI-​generated image: ETH Zurich)

An April 8, 2024 ETH Zurich press release (also on EurekAlert) by Fabio Bergamin features an approach that could make passwords secure from quantum computers, Note: A link has been removed,

Security experts fear Q-​Day, the day when quantum computers become so powerful that they can crack today’s passwords. Some experts estimate that this day will come within the next ten years. Password checks are based on cryptographic one-​way functions, which calculate an output value from an input value. This makes it possible to check the validity of a password without transmitting the password itself: the one-​way function converts the password into an output value that can then be used to check its validity in, say, online banking. What makes one-​way functions special is that it’s impossible to use their output value to deduce the input value – in other words, the password. At least not with today’s resources. However, future quantum computers could make this kind of inverse calculation easier.

Researchers at ETH Zurich have now presented a cryptographic one-​way function that works differently from today’s and will also be secure in the future. Rather than processing the data using arithmetic operations, it is stored as a sequence of nucleotides – the chemical building blocks of DNA.

Based on true randomness

“Our system is based on true randomness. The input and output values are physically linked, and it’s only possible to get from the input value to the output value, not the other way round,” explains Robert Grass, a professor in the Department of Chemistry and Applied Biosciences. “Since it’s a physical system and not a digital one, it can’t be decoded by an algorithm, not even by one that runs on a quantum computer,” adds Anne Lüscher, a doctoral student in Grass’s group. She is the lead author of the paper, which was published in the journal Nature Communications.

The researchers’ new system can serve as a counterfeit-​proof way of certifying the authenticity of valuable objects such as works of art. The technology could also be used to trace raw materials and industrial products.

How it works

The new biochemical one-​way function is based on a pool of one hundred million different DNA molecules. Each of the molecules contains two segments featuring a random sequence of nucleotides: one segment for the input value and one for the output value. There are several hundred identical copies of each of these DNA molecules in the pool, and the pool can also be divided into several pools; these are identical because they contain the same random DNA molecules. The pools can be located in different places, or they can be built into objects.

Anyone in possession of this DNA pool holds the security system’s lock. The polymerase chain reaction (PCR) can be used to test a key, or input value, which takes the form of a short sequence of nucleotides. During the PCR, this key searches the pool of hundreds of millions of DNA molecules for the molecule with the matching input value, and the PCR then amplifies the output value located on the same molecule. DNA sequencing is used to make the output value readable.

At first glance, the principle seems complicated. “However, producing DNA molecules with built-​in randomness is cheap and easy,” Grass says. The production costs for a DNA pool that can be divided up in this way are less than 1 Swiss franc. Using DNA sequencing to read out the output value is more time-​consuming and expensive, but many biology laboratories already possess the necessary equipment.

Securing valuable goods and supply chains

ETH Zurich has applied for a patent on this new technology. The researchers now want to optimise and refine it to bring it to market. Because using the method calls for specialised laboratory infrastructure, the scientists think the most likely application for this form of password verification is currently for highly sensitive goods or for access to buildings with restricted access. This technology won’t be an option for the broader public to check passwords until DNA sequencing in particular becomes easier.

A little more thought has already gone into the idea of using the technology for the forgery-​proof certification of works of art. For instance, if there are ten copies of a picture, the artist can mark them all with the DNA pool – perhaps by mixing the DNA into the paint, spraying it onto the picture or applying it to a specific spot.

If several owners later wish to have the authenticity of these artworks confirmed, they can get together, agree on a key (i.e. an input value) and carry out the DNA test. All the copies for which the test produces the same output value will have been proven genuine. The new technology could also be used to link crypto-​assets such as NFTs, which exist only in the digital world, to an object and thus to the physical world.

Furthermore, it would support counterfeit-​proof tracking along supply chains of industrial goods or raw materials. “The aviation industry, for example, has to be able to provide complete proof that it uses only original components. Our technology can guarantee traceability,” Grass says. In addition, the method could be used to label the authenticity of original medicines or cosmetics.

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

Chemical unclonable functions based on operable random DNA pools by Anne M. Luescher, Andreas L. Gimpel, Wendelin J. Stark, Reinhard Heckel & Robert N. Grass. Nature Communications volume 15, Article number: 2955 (2024) DOI: https://doi.org/10.1038/s41467-024-47187-7 Published: 05 April 2024

This paper is open access.

Deriving gold from electronic waste

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Caption: The gold nugget obtained from computer motherboards in three parts. The largest of these parts is around five millimetres wide. Credit: (Photograph: ETH Zurich / Alan Kovacevic)

A March 1, 2024 ETH Zurich press release (also on EurekAlert but published February 29, 2024) by Fabio Bergamin describes research into reclaiming gold from electronic waste, Note: A link has been removed.

In brief

  • Protein fibril sponges made by ETH Zurich researchers are hugely effective at recovering gold from electronic waste.
  • From 20 old computer motherboards, the researchers retrieved a 22-​carat gold nugget weighing 450 milligrams.
  • Because the method utilises various waste and industry byproducts, it is not only sustainable but cost effective as well.

Transforming base materials into gold was one of the elusive goals of the alchemists of yore. Now Professor Raffaele Mezzenga from the Department of Health Sciences and Technology at ETH Zurich has accomplished something in that vein. He has not of course transformed another chemical element into gold, as the alchemists sought to do. But he has managed to recover gold from electronic waste using a byproduct of the cheesemaking process.

Electronic waste contains a variety of valuable metals, including copper, cobalt, and even significant amounts of gold. Recovering this gold from disused smartphones and computers is an attractive proposition in view of the rising demand for the precious metal. However, the recovery methods devised to date are energy-​intensive and often require the use of highly toxic chemicals. Now, a group led by ETH Professor Mezzenga has come up with a very efficient, cost-​effective, and above all far more sustainable method: with a sponge made from a protein matrix, the researchers have successfully extracted gold from electronic waste.

Selective gold adsorption

To manufacture the sponge, Mohammad Peydayesh, a senior scientist in Mezzenga’s Group, and his colleagues denatured whey proteins under acidic conditions and high temperatures, so that they aggregated into protein nanofibrils in a gel. The scientists then dried the gel, creating a sponge out of these protein fibrils.

To recover gold in the laboratory experiment, the team salvaged the electronic motherboards from 20 old computer motherboards and extracted the metal parts. They dissolved these parts in an acid bath so as to ionise the metals.

When they placed the protein fibre sponge in the metal ion solution, the gold ions adhered to the protein fibres. Other metal ions can also adhere to the fibres, but gold ions do so much more efficiently. The researchers demonstrated this in their paper, which they have published in the journal Advanced Materials.

As the next step, the researchers heated the sponge. This reduced the gold ions into flakes, which the scientists subsequently melted down into a gold nugget. In this way, they obtained a nugget of around 450 milligrams out of the 20 computer motherboards. The nugget was 91 percent gold (the remainder being copper), which corresponds to 22 carats.

Economically viable

The new technology is commercially viable, as Mezzenga’s calculations show: procurement costs for the source materials added to the energy costs for the entire process are 50 times lower than the value of the gold that can be recovered.

Next, the researchers want to develop the technology to ready it for the market. Although electronic waste is the most promising starting product from which they want to extract gold, there are other possible sources. These include industrial waste from microchip manufacturing or from gold-​plating processes. In addition, the scientists plan to investigate whether they can manufacture the protein fibril sponges out of other protein-​rich byproducts or waste products from the food industry.

“The fact I love the most is that we’re using a food industry byproduct to obtain gold from electronic waste,” Mezzenga says. In a very real sense, he observes, the method transforms two waste products into gold. “You can’t get much more sustainable than that!”

If you have a problem accessing either of the two previously provided links to the press release, you can try this February 29, 2024 news item on ScienceDaily.

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

Gold Recovery from E-Waste by Food-Waste Amyloid Aerogels by Mohammad Peydayesh, Enrico Boschi, Felix Donat, Raffaele Mezzenga. DOI: https://doi.org/10.1002/adma.202310642 First published online: 23 January 2024

This paper is open access.

Digi, Nano, Bio, Neuro – why should we care more about converging technologies?

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Personality in focus: the convergence of biology and computer technology could make extremely sensitive data available. (Image: by-​studio / AdobeStock) [downloaded from https://ethz.ch/en/news-and-events/eth-news/news/2024/05/digi-nano-bio-neuro-or-why-we-should-care-more-about-converging-technologies.html]

I gave a guest lecture some years ago where I mentioned that I thought the real issue with big data and AI (artificial intelligence) lay in combining them (or convergence). These days, it seems I was insufficiently imaginative as researchers from ETH Zurich have taken the notion much further.

From a May 7, 2024 ETH Zurich press release (also on EurekAlert), Note: You’ll see in the ‘References’ some extra words, ‘external page’ is self-explanatory but ‘call made’ remains a mystery to me,

In my research, I [Dirk Helbing, Professor of Computational Social Science at the Department of Humanities, Social and Political Sciences and associated with the Department of Computer Science at ETH Zurich.] deal with the consequences of digitalisation for people, society and democracy. In this context, it is also important to keep an eye on their convergence in computer and life sciences – i.e. what becomes possible when digital technologies grow increasingly together with biotechnology, neurotechnology and nanotechnology.

Converging technologies are seen as a breeding ground for far-​reaching innovations. However, they are blurring the boundaries between the physical, biological and digital worlds. Conventional regulations are becoming ineffective as a result.

In a joint study I conducted with my co-​author Marcello Ienca, we have recently examined the risks and societal challenges of technological convergence – and concluded that the effects for individuals and society are far-​reaching.

We would like to draw attention to the challenges and risks of converging technologies and explain why we consider it necessary to accompany technological developments internationally with strict regulations.

For several years now, everyone has been able to observe, within the context of digitalisation, the consequences of leaving technological change to market forces alone without effective regulation.

Misinformation and manipulation on the web

The Digital Manifesto was published in 2015 – almost ten years ago.1 Nine European experts, including one from ETH Zurich, issued an urgent warning against scoring, i.e. the evaluation of people, and big nudging,2 a subtle form of digital manipulation. The latter is based on personality profiles created using cookies and other surveillance data. A little later, the Cambridge Analytica scandal alerted the world to how the data analysis company had been using personalised ads (microtargeting) in an attempt to manipulate voting behaviour in democratic elections.

This has brought democracies around the world under considerable pressure. Propaganda, fake news and hate speech are polarising and sowing doubt, while privacy is on the decline. We are in the midst of an international information war for control of our minds, in which advertising companies, tech corporations, secret services and the military are fighting to exert an influence on our mindset and behaviour. The European Union has adopted the AI Act in an attempt to curb these dangers.

However, digital technologies have developed at a breathtaking pace, and new possibilities for manipulation are already emerging. The merging of digital and nanotechnology with modern biotechnology and neurotechnology makes revolutionary applications possible that had been hardly imaginable before.

Microrobots for precision medicine

In personalised medicine, for example, the advancing miniaturisation of electronics is making it increasingly possible to connect living organisms and humans with networked sensors and computing power. The WEF [World Economic Forum] proclaimed the “Internet of Bodies” as early as 2020.3, 4

One example that combines conventional medication with a monitoring function is digital pills. These could control medication and record a patient’s physiological data (see this blog post).

Experts expect sensor technology to reach the nanoscale. Magnetic nanoparticles or nanoelectronic components, i.e. tiny particles invisible to the naked eye with a diameter up to 100 nanometres, would make it possible to transport active substances, interact with cells and record vast amounts of data on bodily functions. If introduced into the body, it is hoped that diseases could be detected at an early stage and treated in a personalised manner. This is often referred to as high-​precision medicine.

Nano-​electrodes record brain function

Miniaturised electrodes that can simultaneously measure and manipulate the activity of thousands of neurons coupled with ever-​improving AI tools for the analysis of brain signals are approaches that are now leading to much-​discussed advances in the brain-​computer interface. Brain activity mapping is also on the agenda. Thanks to nano-​neurotechnology, we could soon envisage smartphones and other AI applications being controlled directly by thoughts.

“Long before precision medicine and neurotechnology work reliably, these technologies will be able to be used against people.” Dirk Helbling

Large-​scale projects to map the human brain are also likely to benefit from this.5 In future, brain activity mapping will not only be able to read our thoughts and feelings but also make them possible of being influenced remotely – the latter would probably be a lot more effective than previous manipulation methods like big nudging.

However, conventional electrodes are not suitable for permanent connection between cells and electronics – this requires durable and biocompatible interfaces. This has given rise to the suggestion of transmitting signals optogenetically, i.e. to control genes in special cells with light pulses.6 This would make the implementation of amazing circuits possible (see this ETH News article [November 11, 2014 press release] “Controlling genes with thoughts” ).

The downside of convergence

Admittedly, the applications mentioned above may sound futuristic, with most of them still visions or in their early stages of development. However, a lot of research is being conducted worldwide and at full speed. The military is also interested in using converging technologies for its own purposes. 7, 8

The downside of convergence is the considerable risks involved, such as state or private players gaining access to highly sensitive data and misusing it to monitor and influence people. The more connected our bodies become, the more vulnerable we will be to cybercrime and hacking. It cannot be ruled out that military applications exist already.5 One thing is clear, however: long before precision medicine and neurotechnology work reliably, these technologies will be able to be used against people.

“We need to regain control of our personal data. To do this, we need genuine informational self-​determination.” Dirk Helbling

The problem is that existing regulations are specific and insufficient to keep technological convergence in check. But how are we to retain control over our lives if it becomes increasingly possible to influence our thoughts, feelings and decisions by digital means?

Converging global regulation is needed

In our recent paper we conclude that any regulation of converging technologies would have to be based on converging international regulations. Accordingly, we outline a new global regulatory framework and propose ten governance principles to close the looming regulatory gap. 9

The framework emphasises the need for safeguards to protect bodily and mental functions from unauthorised interference and to ensure personal integrity and privacy by, for example. establishing neurorights.

To minimise risks and prevent abuse, future regulations should be inclusive, transparent and trustworthy. The principle of participatory governance is key, which would have to involve all the relevant groups and ensure that the concerns of affected minorities are also taken into account in decision-​making processes.

Finally, we need to regain control of our personal data. To accomplish this, we need genuine informational self-​determination. This would also have to apply to the digital twins of our body and personality, because they can be used to hack our health and our way of thinking – for good or for bad.10

With our contribution, we would like to initiate public debate about converging technologies. Despite its major relevance, we believe that too little attention is being paid to this topic. Continuous discourse on benefits, risks and sensible rules can help to steer technological convergence in such a way that it serves people instead of harming them.

Dirk Helbing wrote this article together with external page Marcello Ienca call_made, who previously worked at ETH Zurich and EPFL and is now Assistant Professor of Ethics of AI and Neuroscience at the Technical University of Munich.

References

1 Digital-​Manifest: external page Digitale Demokratie statt Datendiktatur call_made (2015) Spektrum der Wissenschaft

2 external page Sie sind das Ziel! call_made (2024) Schweizer Monat

3 external page The Internet of Bodies Is Here: Tackling new challenges of technology governance call_made (2020) World Economic Forum

4 external page Tracking how our bodies work could change our lives call_made (2020) World Economic Forum

5 external page Nanotools for Neuroscience and Brain Activity Mapping call_made (2013) ACS Nano

6 external page Innovationspotenziale der Mensch-​Maschine-Interaktion call_made (2016) Deutsche Akademie der Technikwissenschaften

7 external page Human Augmentation – The Dawn of a New Paradigm. A strategic implications project call_made (2021) UK Ministry of Defence

8 external page Behavioural change as the core of warfighting call_made (2017) Militaire Spectator

9 Helbing D, Ienca M: external page Why converging technologies need converging international regulation call_made (2024) Ethics and Information Technology

10 external page Who is Messing with Your Digital Twin? Body, Mind, and Soul for Sale? call_made Dirk Helbing TEDx Talk (2023)

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

Why converging technologies need converging international regulation by Dirk Helbing & Marcello Ienca. Ethics and Information Technology Volume 26, article number 15, (2024) DOI: 10.1007/s10676-024-09756-8 Published: 28 February 2024

This paper is open access.

Bioinspired, biomimetic stimulation for the next generation of neuroprosthetics

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ETH researchers have developed a prosthetic leg that communicates with the brain via natural signals. (Photograph: Keystone) Courtesy: ETH Zurich

A February 21, 2024 ETH Zurich press release by Ori Schipper (also on EurekAlert) announces a ‘nature-inspired’ or bioinspired approach to neuroprosthetics,

Prostheses that connect to the nervous system have been available for several years. Now, researchers at ETH Zurich have found evidence that neuroprosthetics work better when they use signals that are inspired by nature.

In brief

*Neuroprostheses are electro-​mechanical devices that are connected to the nervous system. As yet, these are unable to provide natural communication with the brain. Instead, they often evoke artificial, unpleasant sensations, similar to a feeling of tingles over the skin.
*This paraesthesia might be caused by overstimulation of the nervous system. ETH Zurich researchers together with colleagues in Germany, Serbia and Russia have proposed that neuroprosthetics should transmit biomimetic signals that are easier for the brain to understand.
*These new findings are relevant to arm and leg prostheses as well as various other aids and devices, including spinal implants and electrodes for brain stimulation. 

A few years ago, a team of researchers working under Professor Stanisa Raspopovic at the ETH Zurich Neuroengineering Lab gained worldwide attention when they announced that their prosthetic legs had enabled amputees to feel sensations from this artificial body part for the first time. Unlike commercial leg prostheses, which simply provide amputees with stability and support, the ETH researchers’ prosthetic device was connected to the sciatic nerve in the test subjects’ thigh via implanted electrodes.

This electrical connection enabled the neuroprosthesis to communicate with the patient’s brain, for example relaying information on the constant changes in pressure detected on the sole of the prosthetic foot when walking. This gave the test subjects greater confidence in their prosthesis – and it enabled them to walk considerably faster on challenging terrains. “Our experimental leg prosthesis succeeded in evoking natural sensations. That’s something current neuroprostheses are mainly unable to do; instead, they mostly evoke artificial, unpleasant sensations,” Raspopovic says.

This is probably because today’s neuroprosthetics are using time-​constant electrical pulses to stimulate the nervous system. “That’s not only unnatural, but also inefficient,” Raspopovic says. In a recently published paper, he and his team used the example of their leg prostheses to highlight the benefits of using naturally inspired, biomimetic stimulation to develop the next generation of neuroprosthetics.

Model simulates activation of nerves in the sole

To generate these biomimetic signals, Natalija Katic – a doctoral student in Raspopovic’s research group – developed a computer model called FootSim. It is based on data collected by collaborators in Canada, who recorded the activity of natural receptors, named mechanoreceptors, in the sole of the foot while touching different points on the feet of volunteers with a vibrating rod.

The model simulates the dynamic behaviour of large numbers of mechanoreceptors in the sole of the foot and generates the neural signals that shoot up the nerves in the leg towards the brain – from the moment the heel strikes the ground and the weight of the body starts to shift forward to the outside of the foot until the toes push off the ground ready for the next step. “Thanks to this model, we can see how semsory receptors from the sole, and the connected nerves, behave during walking or running, which is experimentally impossible to measure” Katic says.

Information overload in the spinal cord

To assess how closely the biomimetic signals calculated by the model correspond to the signals emitted by real neurons, Giacomo Valle – a postdoc in Raspopovic’s research group – worked with colleagues in Germany, Serbia and Russia on experiments with cats, whose nervous system processes movement in a similar way to that of humans. The experiments took place in 2019 at the Pavlov Institute of Physiology in St. Petersburg and were carried out in accordance with the relevant European Union guidelines.

The researchers implanted electrodes, connecting some to the nerve in the leg and some to the spinal cord to discover how the signals are transmitted through the nervous system. When the researchers applied pressure to the bottom of the cat’s paw, thereby evoking the natural neural response that occurs when a cat takes a step, the peculiar pattern of activity recorded in the spinal cord did indeed resemble the patterns that were elicited in the spinal cord when the researchers stimulated the leg nerve with biomimetic signals.

By contrast, the conventional approach of time-​constant stimulation of the sciatic nerve in the cat’s thigh elicited a markedly different pattern of activation in the spinal cord. “This clearly shows that the commonly used stimulation methods cause the neural networks in the spine to be flooded with information,” Valle says. “This information overload could be the reason for the unpleasant sensations or paraesthesia reported by some users of neuroprosthetics,” Raspopovic adds.

Learning the language of the nervous system

In their clinical trial with leg amputees, the researchers were able to show that biomimetic stimulation is superior to time-​constant stimulation. Their work clearly demonstrated how the signals that mimicked nature produced better results: not only were the test subjects able to climb steps faster, they also made fewer mistakes in a task that required them to climb the same steps while spelling words backwards. “Biomimetic neurostimulation allows subjects to concentrate on other things while walking,” Raspopovic says, “so we concluded that this type of stimulation is more naturally processed and less taxing on the brain.”

Raspopovic, whose lab forms part of the ETH Institute of Robotics and Intelligent Systems, believes that these new findings are not only relevant to the limb prostheses he and his team have been working on for over half a decade. He argues that the need to move away from unnatural, time-​constant stimulation towards biomimetic signals also applies to a whole series of other aids and devices, including spinal implants and electrodes for brain stimulation. “We need to learn the language of the nervous system,” Raspopovic says. “Then we’ll be able to communicate with the brain in ways it really understands.”

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

Biomimetic computer-to-brain communication enhancing naturalistic touch sensations via peripheral nerve stimulation by Giacomo Valle, Natalija Katic Secerovic, Dominic Eggemann, Oleg Gorskii, Natalia Pavlova, Francesco M. Petrini, Paul Cvancara, Thomas Stieglitz, Pavel Musienko, Marko Bumbasirevic & Stanisa Raspopovic. Nature Communications volume 15, Article number: 1151 (2024) DOI: https://doi.org/10.1038/s41467-024-45190-6 Published: 20 February 2024

This paper is open access.

It was a bit of a surprise to see mention of some Canadian collaborators with regard to the earlier work featuring FootSim, a computer model Here’s a link to and a citation to that paper, this version is housed at ETH Zurich,

Modeling foot sole cutaneous afferents: FootSim by Natalija Katic, Rodrigo Kazu Siqueira, Luke Cleland, Nicholas Strzalkowski, Leah Bent, Stanisa Raspopovic, and Hannes Saal. Originally published in: iScience 26(1), DOI https://doi.org/10.1016/j.isci.2022.105874 Publication date: 2023-01-20 Permanent link: https://doi.org/10.3929/ethz-b-000591102

This paper too is open access.

Be a citizen scientist: join the ‘Wild river battle’

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I got this invitation from a professor at the University of Montpellier (Université de Montpellier, France) in a February 1, 2024 email (the project ‘Wild river battle’ is being run by scientists at ETH Zurich [Swiss Federal Institute of Technology in Zürich]) ,

Dear all,

I hope this message finds you well. I am reaching out to share an exciting opportunity for all of us to contribute to the safeguarding of wild rivers worldwide.

We are launching a Citizen Science project in collaboration with Citizen Science Zurich, utilizing AI and satellite imagery to assess and protect the natural state of rivers on a global scale. Whether you have a passion for river conservation or simply wish to contribute to a meaningful cause, we invite you to join us in this impactful game.

To access the game, please follow this link https://lab.citizenscience.ch/en/project/769

It only takes 3-5 minutes, and the rules are simple: click on the riverscape that you find the wildest (you can also use the buttons under the images).

Thank you very much for your time in advance, and I look forward to witnessing our collective efforts make a positive impact for the conservation of our precious rivers. And we are open to receive any feedback by mail (shzong@ethz.ch) and willing to provide more information for those who are interested (https://ele.ethz.ch/research/technology-modelling/citizen-river.html).

Best regards and have fun!

Nicolas Mouquet

Scientific director of the Centre for the Synthesis
and Analysis of Biodiversity (CESAB)
5 Rue de l’École de Médecine
34000, Montpellier

I went looking for more information as per Mouquet`s email (https://ele.ethz.ch/research/technology-modelling/citizen-river.html) and found this,

Finding wild rivers with AI

A citizen science project combining AI and satellite images to evaluate rivers’ wildness.

Wild rivers are an invaluable resource that play a vital role in maintaining healthy ecosystems and supporting biodiversity. Rivers of high ecological integrity provide habitat for a wide variety of plant and animal species, and their free-​flowing waters provide a large number of services such as freshwater, supporting the needs of local communities. Protecting wild rivers is essential to ensure long-​term global health, and it is our responsibility to develop management schemes to preserve these precious habitats for future generations.  

Wild stretches, supporting the highest levels of biodiversity, are disappearing globally at an extremely fast rate. Deforestation, mining, pollution, booming hydropower dams and other human infrastructures are built or planned on large rivers. The increasing pressure of human activities has been causing a rapid decline of biodiversity and ecological function. We should act now to protect the rivers and be guided by the current state of rivers to identify unprotected areas that are worth being included in conservation plans. However, there is still no map of global wild river segments which could support such global conservation planning, nor a tool to monitor the wilderness of rivers over time under global changes.

How we find wild rivers, evaluate their wildness, and why we need your help

We will evaluate the level of wildness of river sections from satellite images. Remote sensing is the most efficient method for monitoring the landscape on a global and dynamic scale. Satellite images contain valuable information about the river’s course, width, depth, shape and surrounding landscape, which allow us to assess how wild they are visually.

You and other citizen scientists can help us score the wildest river sections from satellite images. Using the ranking from citizen scientists, we will run a ranking algorithm to give each image a wildness score depending on the many pairwise comparisons. These images with a wilderness score will act as a training dataset for a machine learning algorithm which will be trained to automatically score any large river segment, globally. With an accurate river wildness model, we will be able to quickly assess the wildness of the global river sections. Using such a tool, we can for instance find the river sections that are still worth protecting. This pristine river map will provide invaluable insights for conservation initiatives and enable targeted actions to safeguard and restore the remaining pristine rivers and monitor the trajectories of rivers around the world.

How to do it?

Rivers will first be segmented into river sections with the surrounding environment as a whole landscape bounding box. The river sections will be identified by citizen scientists and your interpretation to form a reference dataset. The game (you can click the corresponding language to access it with different language versions. English, French, German, Spanish, Chinese) is easy (thanks to Citizen Science Zurich); you just have to click on the riverscape you find more wild, or click the button under the rivers. For mobile users, please use the buttons.

…

Before you get started there will be this,

Your participation in the study is voluntary.

Statement of consent

By participating in the study, I confirm that I:

* have heard/read and understood the study information.
* had enough time to decide on my participation in the study.
* voluntarily participate in the study and agree to my personal data being used as described below.

Participants’ information will be handled with the utmost confidentiality. All data collected, including but not limited to demographic details, responses to survey questions, and any other pertinent information, will be securely stored and accessible only to authorized personnel involved in the research. Your personal identity will be kept strictly confidential, and any published results will be presented in aggregate form, ensuring that individual participants cannot be identified. Furthermore, your data will not be shared with any third parties and will only be used for the specific research purposes outlined in the introduction page prior to participating in the study.

I fund this description of the researchers and contributors (from https://lab.citizenscience.ch/en/project/769 or ‘Wild river battle’)

…

Who is behind

We are ecologists at ETH Zurich that are foucusing on biodiversity monitoring in the large river corridors. Learn more about us from our homepage. Chair of Ecosystems and Landscape Evolution

Who contributes

All the people that have interest in protecting wild rivers can participate this project, and of course non-governmental organizations (NGOs) and river management bureau like CNR (Compagnie Nationale du Rhône) also showed great interests in this project.

…

Should you be inspired to do more, Citizen Science Zurich lists a number of projects (ranging from the Hair SALON project to FELIDAE: Finding Elusive Links by Tracking Diet of Cats in Environment to more) on this page. It’s a mixed listing of those that are completed or looking for participants and/or looking for financial resources.

There is also a Citizen Science Portal (a Canadian federal government project) that was last updated January 15, 2024. Some of the projects are national in scope while others are provincial in scope.

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

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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.

Memristors based on halide perovskite nanocrystals are more powerful and easier to manufacture

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A March 8, 2023 news item on phys.org announces research from Swiss and Italian researchers into a new type of memristor,

Researchers at Empa, ETH Zurich and the Politecnico di Milano are developing a new type of computer component that is more powerful and easier to manufacture than its predecessors. Inspired by the human brain, it is designed to process large amounts of data fast and in an energy-efficient way.

In many respects, the human brain is still superior to modern computers. Although most people can’t do math as fast as a computer, we can effortlessly process complex sensory information and learn from experiences, while a computer cannot – at least not yet. And, the brain does all this by consuming less than half as much energy as a laptop.

One of the reasons for the brain’s energy efficiency is its structure. The individual brain cells – the neurons and their connections, the synapses – can both store and process information. In computers, however, the memory is separate from the processor, and data must be transported back and forth between these two components. The speed of this transfer is limited, which can slow down the whole computer when working with large amounts of data.

One possible solution to this bottleneck are novel computer architectures that are modeled on the human brain. To this end, scientists are developing so-called memristors: components that, like brain cells, combine data storage and processing. A team of researchers from Empa, ETH Zurich and the “Politecnico di Milano” has now developed a memristor that is more powerful and easier to manufacture than its predecessors. The researchers have recently published their results in the journal Science Advances.

…

A March 8, 2023 Swiss Federal Laboratories for Materials Science and Technology (EMPA) press release (also on EurekAlert), which originated the news item, provides details about what makes this memristor different,

Performance through mixed ionic and electronic conductivity

The novel memristors are based on halide perovskite nanocrystals, a semiconductor material known from solar cell manufacturing. “Halide perovskites conduct both ions and electrons,” explains Rohit John, former ETH Fellow and postdoctoral researcher at both ETH Zurich and Empa. “This dual conductivity enables more complex calculations that closely resemble processes in the brain.”

The researchers conducted the experimental part of the study entirely at Empa: They manufactured the thin-film memristors at the Thin Films and Photovoltaics laboratory and investigated their physical properties at the Transport at Nanoscale Interfaces laboratory. Based on the measurement results, they then simulated a complex computational task that corresponds to a learning process in the visual cortex in the brain. The task involved determining the orientation of light based on signals from the retina.

“As far as we know, this is only the second time this kind of computation has been performed on memristors,” says Maksym Kovalenko, professor at ETH Zurich and head of the Functional Inorganic Materials research group at Empa. “At the same time, our memristors are much easier to manufacture than before.” This is because, in contrast to many other semiconductors, perovskites crystallize at low temperatures. In addition, the new memristors do not require the complex preconditioning through application of specific voltages that comparable devices need for such computing tasks. This makes them faster and more energy-efficient.

Complementing rather than replacing

The technology, though, is not quite ready for deployment yet. The ease with which the new memristors can be manufactured also makes them difficult to integrate with existing computer chips: Perovskites cannot withstand temperatures of 400 to 500 degrees Celsius that are needed to process silicon – at least not yet. But according to Daniele Ielmini, professor at the “Politecnico di Milano”, that integration is key to the success for new brain-like computer technologies. “Our goal is not to replace classical computer architecture,” he explains. “Rather, we want to develop alternative architectures that can perform certain tasks faster and with greater energy efficiency. This includes, for example, the parallel processing of large amounts of data, which is generated everywhere today, from agriculture to space exploration.”

Promisingly, there are other materials with similar properties that could be used to make high-performance memristors. “We can now test our memristor design with different materials,” says Alessandro Milozzi, a doctoral student at the “Politecnico di Milano”. “It is quite possible that some of them are better suited for integration with silicon.”

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

Ionic-electronic halide perovskite memdiodes enabling neuromorphic computing with a second-order complexity by Rohit Abraham John, Alessandro Milozzi, Sergey Tsarev, Rolf Brönnimann, Simon C. Boehme, Erfu Wu, Ivan Shorubalko, Maksym V. Kovalenko, and Daniele Ielmini. Science Advances 23 Dec 2022 Vol 8, Issue 51 DOI: 10.1126/sciadv.ade0072

This paper is open access.

Graphene can be used in quantum components

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A November 3, 2022 news item on phys.org provides a brief history of graphene before announcing the latest work from ETH Zurich,

Less than 20 years ago, Konstantin Novoselov and Andre Geim first created two-dimensional crystals consisting of just one layer of carbon atoms. Known as graphene, this material has had quite a career since then.

Due to its exceptional strength, graphene is used today to reinforce products such as tennis rackets, car tires or aircraft wings. But it is also an interesting subject for fundamental research, as physicists keep discovering new, astonishing phenomena that have not been observed in other materials.

The right twist

Bilayer graphene crystals, in which the two atomic layers are slightly rotated relative to each other, are particularly interesting for researchers. About one year ago, a team of researchers led by Klaus Ensslin and Thomas Ihn at ETH Zurich’s Laboratory for Solid State Physics was able to demonstrate that twisted graphene could be used to create Josephson junctions, the fundamental building blocks of superconducting devices.

Based on this work, researchers were now able to produce the first superconducting quantum interference device, or SQUID, from twisted graphene for the purpose of demonstrating the interference of superconducting quasiparticles. Conventional SQUIDs are already being used, for instance in medicine, geology and archaeology. Their sensitive sensors are capable of measuring even the smallest changes in magnetic fields. However, SQUIDs work only in conjunction with superconducting materials, so they require cooling with liquid helium or nitrogen when in operation.

In quantum technology, SQUIDs can host quantum bits (qubits); that is, as elements for carrying out quantum operations. “SQUIDs are to superconductivity what transistors are to semiconductor technology—the fundamental building blocks for more complex circuits,” Ensslin explains.

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A November 3, 2022 ETH Zurich news release by Felix Würsten, which originated the news item, delves further into the work,

The spectrum is widening

The graphene SQUIDs created by doctoral student Elías Portolés are not more sensitive than their conventional counterparts made from aluminium and also have to be cooled down to temperatures lower than 2 degrees above absolute zero. “So it’s not a breakthrough for SQUID technology as such,” Ensslin says. However, it does broaden graphene’s application spectrum significantly. “Five years ago, we were already able to show that graphene could be used to build single-electron transistors. Now we’ve added superconductivity,” Ensslin says.

What is remarkable is that the graphene’s behaviour can be controlled in a targeted manner by biasing an electrode. Depending on the voltage applied, the material can be insulating, conducting or superconducting. “The rich spectrum of opportunities offered by solid-state physics is at our disposal,” Ensslin says.

Also interesting is that the two fundamental building blocks of a semiconductor (transistor) and a superconductor (SQUID) can now be combined in a single material. This makes it possible to build novel control operations. “Normally, the transistor is made from silicon and the SQUID from aluminium,” Ensslin says. “These are different materials requiring different processing technologies.”

An extremely challenging production process

Superconductivity in graphene was discovered by an MIT [Massachusetts Institute of Technology] research group five years ago, yet there are only a dozen or so experimental groups worldwide that look at this phenomenon. Even fewer are capable of converting superconducting graphene into a functioning component.

The challenge is that scientists have to carry out several delicate work steps one after the other: First, they have to align the graphene sheets at the exact right angle relative to each other. The next steps then include connecting electrodes and etching holes. If the graphene were to be heated up, as happens often during cleanroom processing, the two layers re-align the twist angle vanishes. “The entire standard semiconductor technology has to be readjusted, making this an extremely challenging job,” Portolés says.

The vision of hybrid systems

Ensslin is thinking one step ahead. Quite a variety of different qubit technologies are currently being assessed, each with its own advantages and disadvantages. For the most part, this is being done by various research groups within the National Center of Competence in Quantum Science and Technology (QSIT). If scientists succeed in coupling two of these systems using graphene, it might be possible to combine their benefits as well. “The result would be two different quantum systems on the same crystal,” Ensslin says.

This would also generate new possibilities for research on superconductivity. “With these components, we might be better able to understand how superconductivity in graphene comes about in the first place,” he adds. “All we know today is that there are different phases of superconductivity in this material, but we do not yet have a theoretical model to explain them.”

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

A tunable monolithic SQUID in twisted bilayer graphene by Elías Portolés, Shuichi Iwakiri, Giulia Zheng, Peter Rickhaus, Takashi Taniguchi, Kenji Watanabe, Thomas Ihn, Klaus Ensslin & Folkert K. de Vries. Nature Nanotechnology volume 17, pages 1159–1164 (2022) Issue Date: November 2022 DOI: https://doi.org/10.1038/s41565-022-01222-0 Published online: 24 October 2022

This paper is behind a paywall.

Exotic magnetism: a quantum simulation from D-Wave Sytems

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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.

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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,

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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.

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

Graphene and its magnetism

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I have two news bits about graphene and magnetism. If I understood what I was reading, one is more focused on applications and the other is focused on further establishing the field of valleytronics.

University of Cambridge and superconductivity

A February 8, 2021 news item on Nanowerk announces ‘magnetic work’ from the University of Cambridge (Note: A link has been removed),

The researchers, led by the University of Cambridge, were able to control the conductivity and magnetism of iron thiophosphate (FePS3), a two-dimensional material which undergoes a transition from an insulator to a metal when compressed. This class of magnetic materials offers new routes to understanding the physics of new magnetic states and superconductivity.

Using new high-pressure techniques, the researchers have shown what happens to magnetic graphene during the transition from insulator to conductor and into its unconventional metallic state, realised only under ultra-high pressure conditions. When the material becomes metallic, it remains magnetic, which is contrary to previous results and provides clues as to how the electrical conduction in the metallic phase works. The newly discovered high-pressure magnetic phase likely forms a precursor to superconductivity so understanding its mechanisms is vital.

Their results, published in the journal Physical Review X, also suggest a way that new materials could be engineered to have combined conduction and magnetic properties, which could be useful in the development of new technologies such as spintronics, which could transform the way in which computers process information.

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A February 8, 2021 University of Cambridge press release (also on EurekAlert), which originated the news item, delves into the topic,

Properties of matter can alter dramatically with changing dimensionality. For example, graphene, carbon nanotubes, graphite and diamond are all made of carbon atoms, but have very different properties due to their different structure and dimensionality.

“But imagine if you were also able to change all of these properties by adding magnetism,” said first author Dr Matthew Coak, who is jointly based at Cambridge’s Cavendish Laboratory and the University of Warwick. “A material which could be mechanically flexible and form a new kind of circuit to store information and perform computation. This is why these materials are so interesting, and because they drastically change their properties when put under pressure so we can control their behaviour.”

In a previous study by Sebastian Haines of Cambridge’s Cavendish Laboratory and the Department of Earth Sciences, researchers established that the material becomes a metal at high pressure, and outlined how the crystal structure and arrangement of atoms in the layers of this 2D material change through the transition.

“The missing piece has remained however, the magnetism,” said Coak. “With no experimental techniques able to probe the signatures of magnetism in this material at pressures this high, our international team had to develop and test our own new techniques to make it possible.”

The researchers used new techniques to measure the magnetic structure up to record-breaking high pressures, using specially designed diamond anvils and neutrons to act as the probe of magnetism. They were then able to follow the evolution of the magnetism into the metallic state.

“To our surprise, we found that the magnetism survives and is in some ways strengthened,” co-author Dr Siddharth Saxena, group leader at the Cavendish Laboratory. “This is unexpected, as the newly-freely-roaming electrons in a newly conducting material can no longer be locked to their parent iron atoms, generating magnetic moments there – unless the conduction is coming from an unexpected source.”

In their previous paper, the researchers showed these electrons were ‘frozen’ in a sense. But when they made them flow or move, they started interacting more and more. The magnetism survives, but gets modified into new forms, giving rise to new quantum properties in a new type of magnetic metal.

How a material behaves, whether conductor or insulator, is mostly based on how the electrons, or charge, move around. However, the ‘spin’ of the electrons has been shown to be the source of magnetism. Spin makes electrons behave a bit like tiny bar magnets and point a certain way. Magnetism from the arrangement of electron spins is used in most memory devices: harnessing and controlling it is important for developing new technologies such as spintronics, which could transform the way in which computers process information.

“The combination of the two, the charge and the spin, is key to how this material behaves,” said co-author Dr David Jarvis from the Institut Laue-Langevin, France, who carried out this work as the basis of his PhD studies at the Cavendish Laboratory. “Finding this sort of quantum multi-functionality is another leap forward in the study of these materials.”

“We don’t know exactly what’s happening at the quantum level, but at the same time, we can manipulate it,” said Saxena. “It’s like those famous ‘unknown unknowns’: we’ve opened up a new door to properties of quantum information, but we don’t yet know what those properties might be.”

There are more potential chemical compounds to synthesise than could ever be fully explored and characterised. But by carefully selecting and tuning materials with special properties, it is possible to show the way towards the creation of compounds and systems, but without having to apply huge amounts of pressure.

Additionally, gaining fundamental understanding of phenomena such as low-dimensional magnetism and superconductivity allows researchers to make the next leaps in materials science and engineering, with particular potential in energy efficiency, generation and storage.

As for the case of magnetic graphene, the researchers next plan to continue the search for superconductivity within this unique material. “Now that we have some idea what happens to this material at high pressure, we can make some predictions about what might happen if we try to tune its properties through adding free electrons by compressing it further,” said Coak.

“The thing we’re chasing is superconductivity,” said Saxena. “If we can find a type of superconductivity that’s related to magnetism in a two-dimensional material, it could give us a shot at solving a problem that’s gone back decades.”

The citation and link to the paper are at the end of this blog posting.

Aalto University’s valleytronics

Further north in Finland, researchers at Aalto University make some advances applicable to the field of valleytronics, from a February 5, 2021 Aalto University press release (also on EurekAltert but published February 8, 2021),

Electrons in materials have a property known as ‘spin’, which is responsible for a variety of properties, the most well-known of which is magnetism. Permanent magnets, like the ones used for refrigerator doors, have all the spins in their electrons aligned in the same direction. Scientists refer to this behaviour as ferromagnetism, and the research field of trying to manipulate spin as spintronics.

Down in the quantum world, spins can arrange in more exotic ways, giving rise to frustrated states and entangled magnets. Interestingly, a property similar to spin, known as “the valley,” appears in graphene materials. This unique feature has given rise to the field of valleytronics, which aims to exploit the valley property for emergent physics and information processing, very much like spintronics relies on pure spin physics.

‘Valleytronics would potentially allow encoding information in the quantum valley degree of freedom, similar to how electronics do it with charge and spintronics with the spin.’ Explains Professor Jose Lado, from Aalto’s Department of applied physics, and one of the authors of the work. ‘What’s more, valleytronic devices would offer a dramatic increase in the processing speeds in comparison with electronics, and with much higher stability towards magnetic field noise in comparison with spintronic devices.’

Structures made of rotated, ultra-thin materials provide a rich solid-state platform for designing novel devices. In particular, slightly twisted graphene layers have recently been shown to have exciting unconventional properties, that can ultimately lead to a new family of materials for quantum technologies. These unconventional states which are already being explored depend on electrical charge or spin. The open question is if the valley can also lead to its own family of exciting states.

Making materials for valleytronics

For this goal, it turns out that conventional ferromagnets play a vital role, pushing graphene to the realms of valley physics. In a recent work, Ph.D. student Tobias Wolf, together with Profs. Oded Zilberberg and Gianni Blatter at ETH Zurich, and Prof. Jose Lado at Aalto University, showed a new direction for correlated physics in magnetic van der Waals materials.

The team showed that sandwiching two slightly rotated layers of graphene between a ferromagnetic insulator provides a unique setting for new electronic states. The combination of ferromagnets, graphene’s twist engineering, and relativistic effects force the “valley” property to dominate the electrons behaviour in the material. In particular, the researchers showed how these valley-only states can be tuned electrically, providing a materials platform in which valley-only states can be generated. Building on top of the recent breakthrough in spintronics and van der Waals materials, valley physics in magnetic twisted van der Waals multilayers opens the door to the new realm of correlated twisted valleytronics.

‘Demonstrating these states represents the starting point towards new exotic entangled valley states.’ Said Professor Lado, ‘Ultimately, engineering these valley states can allow realizing quantum entangled valley liquids and fractional quantum valley Hall states. These two exotic states of matter have not been found in nature yet, and would open exciting possibilities towards a potentially new graphene-based platform for topological quantum computing.’

Citations and links

Here’s a link to and a citation for the University of Cambridge research,

Emergent Magnetic Phases in Pressure-Tuned van der Waals Antiferromagnet FePS3 by Matthew J. Coak, David M. Jarvis, Hayrullo Hamidov, Andrew R. Wildes, Joseph A. M. Paddison, Cheng Liu, Charles R. S. Haines, Ngoc T. Dang, Sergey E. Kichanov, Boris N. Savenko, Sungmin Lee, Marie Kratochvílová, Stefan Klotz, Thomas C. Hansen, Denis P. Kozlenko, Je-Geun Park, and Siddharth S. Saxena. Phys. Rev. X 11, 011024 DOI: https://doi.org/10.1103/PhysRevX.11.011024 Published 5 February 2021

This article appears to be open access.

Here’s a link to and a citation for the Aalto University research,

Spontaneous Valley Spirals in Magnetically Encapsulated Twisted Bilayer Graphene by Tobias M. R. Wolf, Oded Zilberberg, Gianni Blatter, and Jose L. Lado. Phys. Rev. Lett. 126, 056803 DOI: https://doi.org/10.1103/PhysRevLett.126.056803 Published 4 February 2021

This paper is behind a paywall.