Tag Archives: particle zoo

Simulating elementary physics in a quantum simulation (particle zoo in a quantum computer?)

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Whoever wrote the news release used a very catchy title “Particle zoo in a quantum computer”; I just wish they’d explained it. Looking up the definition for a ‘particle zoo’ didn’t help as much as I’d hoped. From the particle zoo entry on Wikipedia (Note: Links have been removed),

In particle physics, the term particle zoo[1][2] is used colloquially to describe a relatively extensive list of the then known “elementary particles” that almost look like hundreds of species in the zoo.

In the history of particle physics, the situation was particularly confusing in the late 1960s. Before the discovery of quarks, hundreds of strongly interacting particles (hadrons) were known, and believed to be distinct elementary particles in their own right. It was later discovered that they were not elementary particles, but rather composites of the quarks. The set of particles believed today to be elementary is known as the Standard Model, and includes quarks, bosons and leptons.

I believe the writer used the term to indicate that the simulation undertaken involved elementary particles. If you have a better explanation, please feel free to add it to the comments for this post.

Here’s the news from a June 22, 2016 news item on ScienceDaily,

Elementary particles are the fundamental buildings blocks of matter, and their properties are described by the Standard Model of particle physics. The discovery of the Higgs boson at the CERN in 2012 constitutes a further step towards the confirmation of the Standard Model. However, many aspects of this theory are still not understood because their complexity makes it hard to investigate them with classical computers. Quantum computers may provide a way to overcome this obstacle as they can simulate certain aspects of elementary particle physics in a well-controlled quantum system. Physicists from the University of Innsbruck and the Institute for Quantum Optics and Quantum Information (IQOQI) at the Austrian Academy of Sciences have now done exactly that: In an international first, Rainer Blatt’s and Peter Zoller’s research teams have simulated lattice gauge theories in a quantum computer. …

A June 23, 2016 University of Innsbruck (Universität Innsbruck) press release, which seems  to have originated the news item, provides more detail,

Gauge theories describe the interaction between elementary particles, such as quarks and gluons, and they are the basis for our understanding of fundamental processes. “Dynamical processes, for example, the collision of elementary particles or the spontaneous creation of particle-antiparticle pairs, are extremely difficult to investigate,” explains Christine Muschik, theoretical physicist at the IQOQI. “However, scientists quickly reach a limit when processing numerical calculations on classical computers. For this reason, it has been proposed to simulate these processes by using a programmable quantum system.” In recent years, many interesting concepts have been proposed, but until now it was impossible to realize them. “We have now developed a new concept that allows us to simulate the spontaneous creation of electron-positron pairs out of the vacuum by using a quantum computer,” says Muschik. The quantum system consists of four electromagnetically trapped calcium ions that are controlled by laser pulses. “Each pair of ions represent a pair of a particle and an antiparticle,” explains experimental physicist Esteban A. Martinez. “We use laser pulses to simulate the electromagnetic field in a vacuum. Then we are able to observe how particle pairs are created by quantum fluctuations from the energy of this field. By looking at the ion’s fluorescence, we see whether particles and antiparticles were created. We are able to modify the parameters of the quantum system, which allows us to observe and study the dynamic process of pair creation.”

Combining different fields of physics

With this experiment, the physicists in Innsbruck have built a bridge between two different fields in physics: They have used atomic physics experiments to study questions in high-energy physics. While hundreds of theoretical physicists work on the highly complex theories of the Standard Model and experiments are carried out at extremely expensive facilities, such as the Large Hadron Collider at CERN, quantum simulations may be carried out by small groups in tabletop experiments. “These two approaches complement one another perfectly,” says theoretical physicist Peter Zoller. “We cannot replace the experiments that are done with particle colliders. However, by developing quantum simulators, we may be able to understand these experiments better one day.” Experimental physicist Rainer Blatt adds: “Moreover, we can study new processes by using quantum simulation. For example, in our experiment we also investigated particle entanglement produced during pair creation, which is not possible in a particle collider.” The physicists are convinced that future quantum simulators will potentially be able to solve important questions in high-energy physics that cannot be tackled by conventional methods.

Foundation for a new research field

It was only a few years ago that the idea to combine high-energy and atomic physics was proposed. With this work it has been implemented experimentally for the first time. “This approach is conceptually very different from previous quantum simulation experiments studying many-body physics or quantum chemistry. The simulation of elementary particle processes is theoretically very complex and, therefore, has to satisfy very specific requirements. For this reason it is difficult to develop a suitable protocol,” underlines Zoller. The conditions for the experimental physicists were equally demanding: “This is one of the most complex experiments that has ever been carried out in a trapped-ion quantum computer,” says Blatt. “We are still figuring out how these quantum simulations work and will only gradually be able to apply them to more challenging phenomena.” The great theoretical as well as experimental expertise of the physicists in Innsbruck was crucial for the breakthrough. Both Blatt and Zoller emphasize that they have been doing research on quantum computers for many years now and have gained a lot of experience in their implementation. Innsbruck has become one of the leading centers for research in quantum physics; here, the theoretical and experimental branches work together at an extremely high level, which enables them to gain novel insights into fundamental phenomena.

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

Real-time dynamics of lattice gauge theories with a few-qubit quantum computer by Esteban A. Martinez, Christine A. Muschik, Philipp Schindler, Daniel Nigg, Alexander Erhard, Markus Heyl, Philipp Hauke, Marcello Dalmonte, Thomas Monz, Peter Zoller, & Rainer Blatt.  Nature 534, 516–519 (23 June 2016)  doi:10.1038/nature18318 Published online 22 June 2016

This paper is behind a paywall.

There is a soundcloud audio file featuring an explanation of the work from the lead author, Esteban A. Martinez,

Playing and singing the Higgs Boson

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The Higgs Boson has lead to an explosion of creativity. First, the Guerilla Science team has produced a Secret Garden Party (July 19 – 22, 2012) featuring the Higgs Boson. Here’s a video clip from the 2012 event,

Zoe Cormier (writer and Guerilla Science co-founder) notes in her July 27, 2012 posting on the Guardian science blogs,

The Particle Zoo Safari, hosted by Guerilla Science at the Secret Garden Party arts and music festival last weekend, observed the formation of another proton and hydrogen atom, the sparring of two combative electrons, polyamorous covalent bond formation, sunlight manufacture through fusion (and a ping pong ball), and the creation of deuterium – complete with dubstep to mirror the atomic weight of the heavy form of hydrogen.

With polystyrene magnets our audience-cum-collider recreated the Large Hadron Collider (LHC) to produce the star of the show: the Higgs boson, sumo-suited and angry, the weightiest particle of all. “I’m hungry,” it grumpily announced, before we threw a net over it and dragged it into the tent. Too much had been spent on the particle’s discovery to let it escape now.

“The idea of the safari came from a colloquialism in physics, which refers to the set of standard particles that make up the entire universe as the ‘particle zoo’,” explains Patrick Stevenson-Keating, the designer we enlisted to help us devise a new way to explore particle physics. “This scale of subatomic particles is so different to our everyday world that there are few comparisons you can really make, so it was challenging to visualise some of the concepts.”

Here’s what the science consultant had to say about it (from Cormier’s posting),

“When I was first approached to take part, I did think it sounded a bit nuts actually, but in the end it worked out reasonably well in terms of the science – I think most people would at least remember that quarks come in threes, and they are difficult to pull apart,” says Dr James Monk of the University College London, a particle physicist who works on the Atlas experiment on the LHC, whom we enlisted as a scientific consultant. “These particles and forces are important to understand how the world works, and it wouldn’t be fitting if physicists said that we do all this fantastic research – but the rest of you can’t possibly understand it.”

It’s well worth reading Cormier’s whole post and you might even feel like taking another look at the video (I found it embedded in Cormier’s posting)  after reading.

(Last year, I featured Guerilla Science and Cormier in my July 12, 2011 posting.)

Meanwhile, the Higgs is producing music. According to David Bruggeman’s July 28, 2012 posting on his Pasco Phronesis blog,

While it seems unlikely that papers will soon come as .mp3 files with audio infographics, some are still working on hearing things we usually expect to see.

…

The idea is to match energy levels found in the data with particular notes.  That way shifts in energy can be more immediately expressed as shifts in tone.  The Higgs boson peaks out of the background noise – noise that isn’t really noise from a musical perspective.

David is hoping turning data into music could be used in the future for educational purposes,

… for those who have an easier time detecting patterns in audio rather than printed data, this could be a very productive development.

I thought it would be interesting to hear some Higgs Boson music. While this piece is based on Higgs data, the composer has taken liberties after letting you hear what the untreated melody sounds like,

The composer, Ben McCormack, had this to say about the piece titled, Higgs Boson (ATLAS preliminary data),

The data was already converted to notes by Domenico Vicinanza. I then consolidated the melody to remove a lot of the large leaps, giving it a slightly better flow.

Before you say anything, I know that this (at least somewhat) defeats the purpose of the data. I’m a composer; my goal was primarily to make a fun piece of music. I inverted the melody and wrote countermelodies that aren’t mathematically-related to the original melody, so consider this more a creative work than an exercise in data analysis.

You can find out more about the Higgs Boson in my July 4, 2012 posting where I wrote about the then latest announcement from CERN (European Particle Physics Laboratory).