Objective Reality May Not Exist at All, Quantum Physicists Say

Stav Dimitropoulos
Sat, July 9, 2022


Photo credit: VICTOR de SCHWANBERG/SCIENCE PHOTO LIBRARY - Getty Images


One of the biggest mysteries in quantum mechanics is whether physical reality exists independent of its observer.

New research from Brazil provides strong evidence that there might be mutually exclusive, yet complementary physical realities in the quantum realm.

Future research on the great quantum debate might give us super-disruptive quantum technologies—and probably startling answers to the world’s greatest mysteries.

Does reality exist, or does it take shape when an observer measures it? Akin to the age-old conundrum of whether a tree makes a sound if it falls in a forest with no one around to hear it, the above question remains one of the most tantalizing in the field of quantum mechanics, the branch of science dealing with the behavior of subatomic particles on the microscopic level.


In a field where intriguing, almost mysterious phenomena like “quantum superposition” prevail—a situation where one particle can be in two or even “all” possible places at the same time—some experts say reality exists outside of your own awareness, and there’s nothing you can do to change it. Others insist “quantum reality” might be some form of Play-Doh you mold into different shapes with your own actions. Now, scientists from the Federal University of ABC (UFABC) in the São Paulo metropolitan area in Brazil are adding fuel to the suggestion that reality might be “in the eye of the observer.”

In their new research, published in the journal Communications Physics in April, the scientists in Brazil attempted to verify the “complementarity principle” the famous Danish physicist Niels Bohr proposed in 1928. It states that objects come with certain pairs of complementary properties, which are impossible to observe or measure at the same time, like energy and duration, or position and momentum. For example, no matter how you set up an experiment involving a pair of electrons, there’s no way you can study the position of both quantities at the same time: the test will illustrate the position of the first electron, but obscure the position of the second particle (the complementary particle) at the same time.
“God Does Not Play Dice”

To understand how this complementarity principle relates to objective reality, we need to dive back into history, about a century ago. A legendary debate took place in Brussels in 1927 between Bohr and the celebrated German-born theoretical physicist Albert Einstein during the fifth Solvay Conference (the most important annual international conference in physics and chemistry).

Photo credit: Science & Society Picture Library - Getty Images

Before the eyes of 77 other brilliant scientists, who had all gathered in the Austrian capital to discuss the nascent field of quantum theory, Einstein insisted that quantum states had their own reality independent of how a scientist acted upon them. Bohr, meanwhile, defended the idea that quantum systems can only have their own reality defined after the scientist has set up the experimental design.

“God does not play dice,” Einstein said.

“A system behaves as a wave or a particle depending on context, but you cannot predict which it will do,” argued Bohr, pointing to the concept of wave-particle duality, which says that matter may appear as a wave in one moment, and appear as a particle in another moment, an idea that French physicist Louis de Broglie first put forth in 1924.
The “Complementarity Principle”

It didn’t take long after the conclusion of the 1927 Solvay Conference for Bohr to publicly articulate his complementarity principle. Over the next few decades, the controversial Bohr notion would be tested and retested to the bone. One of those that experimented with the complementarity principle was American theoretical physicist John Archibald Wheeler.

Wheeler attempted to reimagine Thomas Young’s 1801 double-slit experiment into the properties of light in 1978. The two-slit experiment involves shining a light on a wall with two parallel slits. As the light passes through each slit, on the far side of the divider, it diffracts and overlaps with the light from the other slit, interfering with one another. That means no more straight lines: the graph pattern that emerges at the end of the experiment is an interference pattern, which means that the light is moving in waves. Essentially, light has both a particle and a wave nature, and these two natures are inseparable.

Wheeler had his device switch between a “wave-measuring apparatus” and a “particle-measuring apparatus” after the light had already traveled through most of the machine. In other words, he made a delayed choice between whether the light had already propagated as a wave or a particle, and found that even after delaying the choice, the principle of complementarity was not violated.

However, more recent surveys, which attempted to apply the quantum superposition principle on the delayed-choice experiment, saw the two possibilities coexist (just as two waves on the surface of a lake can overlap). This suggested a hybrid wave-like and particle-like behavior within the same apparatus, contradicting the complementarity principle.

Quantum-Controlled Reality

The Brazilian scientists decided to also design a quantum-controlled reality experiment.

“We used nuclear magnetic resonance techniques similar to those used in medical imaging,” Roberto M. Serra, a quantum information science and technology researcher at UFABC, who led the experiment, tells Popular Mechanics. Particles like protons, neutrons, and electrons all have a nuclear spin, which is a magnetic property analogous to the orientation of a needle in a compass. “We manipulated these nuclear spins of different atoms in a molecule employing a type of electromagnetic radiation. In this setup, we created a new interference device for a proton nuclear spin to investigate its wave and particle reality in the quantum realm,” Serra explains.

“This new arrangement produced exactly the same observed statistics as previous quantum delayed-choice experiments,” Pedro Ruas Dieguez, now a postdoctoral research fellow at the International Centre for Theory of Quantum Technologies (ICTQT) in Poland, who was part of the study, tells Popular Mechanics. “However, in the new configuration, we were able to connect the result of the experiment with the way waves and particles behave in a way that verifies Bohr’s complementarity principle,” Dieguez continues.

The main takeaway from the April 2022 study is that physical reality in the quantum world is made of mutually exclusive entities that, nonetheless, do not contradict but complete each other.

This is a fascinating result, experts say. “The Brazilian researchers have devised a mathematical framework and corresponding experimental configuration that allows the testing of quantum theory, particularly understanding the nature of complementarity by studying the physical realism of the system,” Stephen Holler, an associate professor of physics at Fordham University, tells Popular Mechanics.

It is a study that highlights the long-standing adage of the iconic American quantum physicist and Nobel laureate Richard Feynman: “If you think you understand quantum mechanics, you don’t understand quantum mechanics,” says Holler. “There’s much to learn about the theory and researchers continue to make strides to understand even basic principles, which is especially important as we move into the age where quantum devices and computing are starting to proliferate.”

Dieguez is elated. “The fact that a material particle may behave like a wave and light like a particle, depending on the context, is still one of the most intriguing and beautiful mysteries of quantum physics,” he says.

Paradoxically, this inherent “weirdness” of quantum mechanics can prove quite serviceable: “The more we unravel quantum mechanics, the more we are able to provide disruptive quantum technologies outshining their classical counterparts, quantum computers, quantum cryptography, quantum sensors, and quantum thermal devices included,” says Serra.

That reality might be in the eye of the observer is a very peculiar aspect of the physical reality in the quantum domain, and the mystery itself shows no signs of abating, both researchers agree.

Magic, is the “Science and Art that provokes

 Change in conformity with the Will”

“all intentional acts are acts of magic.”

How philosophy turned into physics and reality turned into information

by Peter Evans, The Conversation

John Bell in his office at CERN in Switzerland. Credit: CERN

The Nobel Prize in physics this year has been awarded "for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science."

To understand what this means, and why this work is important, we need to understand how these experiments settled a long-running debate among physicists. And a key player in that debate was an Irish physicist named John Bell.

In the 1960s, Bell figured out how to translate a philosophical question about the nature of reality into a physical question that could be answered by science—and along the way broke down the distinction between what we know about the world and how the world really is.

Quantum entanglement

We know that quantum objects have properties we don't usually ascribe to the objects of our ordinary lives. Sometimes light is a wave, sometimes it's a particle. Our fridge never does this.

When attempting to explain this sort of unusual behavior, there are two broad types of explanation we can imagine. One possibility is that we perceive the quantum world clearly, just as it is, and it just so happens to be unusual. Another possibility is that the quantum world is just like the ordinary world we know and love, but our view of it is distorted, so we can't see quantum reality clearly, as it is.

In the early decades of the 20th century, physicists were divided about which explanation was right. Among those who thought the quantum world just is unusual were figures such as Werner Heisenberg and Niels Bohr. Among those who thought the quantum world must be just like the ordinary world, and our view of it is simply foggy, were Albert Einstein and Erwin Schrödinger.

At the heart of this division is an unusual prediction of quantum theory. According to the theory, the properties of certain quantum systems that interact remain dependent on each other—even when the systems have been moved a great distance apart.

In 1935, the same year he devised his famous thought experiment involving a cat trapped in a box, Schrödinger coined the term "entanglement" for this phenomenon. He argued it is absurd to believe the world works this way.

The problem with entanglement

If entangled quantum systems really remain connected even when they are separated by large distances, it would seem they are somehow communicating with each other instantaneously. But this sort of connection is not allowed, according to Einstein's theory of relativity. Einstein called this idea "spooky action at a distance."

Again in 1935, Einstein, along with two colleagues, devised a thought experiment that showed quantum mechanics can't be giving us the whole story on entanglement. They thought there must be something more to the world that we can't yet see.

But as time passed, the question of how to interpret quantum theory became an academic footnote. The question seemed too philosophical, and in the 1940s many of the brightest minds in quantum physics were busy using the theory for a very practical project: building the atomic bomb.

It wasn't until the 1960s, when Irish physicist John Bell turned his mind to the problem of entanglement, that the scientific community realized this seemingly philosophical question could have a tangible answer.

Bell's theorem

Using a simple entangled system, Bell extended Einstein's 1935 thought experiment. He showed there was no way the quantum description could be incomplete while prohibiting "spooky action at a distance" and still matching the predictions of quantum theory.

Not great news for Einstein, it seems. But this was not an instant win for his opponents.

This is because it was not evident in the 1960s whether the predictions of quantum theory were indeed correct. To really prove Bell's point, someone had to put this philosophical argument about reality, transformed into a real physical system, to an experimental test.

And this, of course, is where two of this year's Nobel laureates enter the story. First John Clauser, and then Alain Aspect, performed the experiments on Bell's proposed system that ultimately showed the predictions of quantum mechanics to be accurate. As a result, unless we accept "spooky action at a distance," there is no further account of entangled quantum systems that can describe the observed quantum world.

So, Einstein was wrong?

It is perhaps a surprise, but these advances in quantum theory appear to have shown Einstein to be wrong on this point. That is, it seems we do not have a foggy view of a quantum world that is just like our ordinary world.

But the idea that we perceive clearly an inherently unusual quantum world is likewise too simplistic. And this provides one of the key philosophical lessons of this episode in quantum physics.

It is no longer clear we can reasonably talk about the quantum world beyond our scientific description of it—that is, beyond the information we have about it.

As this year's third Nobel laureate, Anton Zeilinger, put it: "The distinction between reality and our knowledge of reality, between reality and information, cannot be made. There is no way to refer to reality without using the information we have about it."

This distinction, which we commonly assume to underpin our ordinary picture of the world, is now irretrievably blurry. And we have John Bell to thank.

What is quantum entanglement? A physicist explains the science of Einstein's 'spooky action at a distance' Provided by The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What is quantum entanglement? A physicist explains the science of Einstein's 'spooky action at a distance'

by Andreas Muller, The Conversation

According to quantum mechanics, particles are simultaneously in two or more states until

 observed – an effect vividly captured by Schrödinger’s famous thought experiment of a

 cat that is both dead and alive simultaneously. 

Credit: Michael Holloway/Wikimedia Commons, CC BY-SA

The 2022 Nobel Prize in physics recognized three scientists who made groundbreaking contributions in understanding one of the most mysterious of all natural phenomena: quantum entanglement.

In the simplest terms, quantum entanglement means that aspects of one particle of an entangled pair depend on aspects of the other particle, no matter how far apart they are or what lies between them. These particles could be, for example, electrons or photons, and an aspect could be the state it is in, such as whether it is "spinning" in one direction or another.

The strange part of quantum entanglement is that when you measure something about one particle in an entangled pair, you immediately know something about the other particle, even if they are millions of light years apart. This odd connection between the two particles is instantaneous, seemingly breaking a fundamental law of the universe. Albert Einstein famously called the phenomenon "spooky action at a distance."

Having spent the better part of two decades conducting experiments rooted in quantum mechanics, I have come to accept its strangeness. Thanks to ever more precise and reliable instruments and the work of this year's Nobel winners, Alain Aspect, John Clauser and Anton Zeilinger, physicists now integrate quantum phenomena into their knowledge of the world with an exceptional degree of certainty.

However, even until the 1970s, researchers were still divided over whether quantum entanglement was a real phenomenon. And for good reasons—who would dare contradict the great Einstein, who himself doubted it? It took the development of new experimental technology and bold researchers to finally put this mystery to rest.

Existing in multiple states at once

To truly understand the spookiness of quantum entanglement, it is important to first understand quantum superposition. Quantum superposition is the idea that particles exist in multiple states at once. When a measurement is performed, it is as if the particle selects one of the states in the superposition.

For example, many particles have an attribute called spin that is measured either as "up" or "down" for a given orientation of the analyzer. But until you measure the spin of a particle, it simultaneously exists in a superposition of spin up and spin down.

There is a probability attached to each state, and it is possible to predict the average outcome from many measurements. The likelihood of a single measurement being up or down depends on these probabilities, but is itself unpredictable.

Though very weird, the mathematics and a vast number of experiments have shown that quantum mechanics correctly describes physical reality.

Two entangled particles

The spookiness of quantum entanglement emerges from the reality of quantum superposition, and was clear to the founding fathers of quantum mechanics who developed the theory in the 1920s and 1930s.

To create entangled particles you essentially break a system into two, where the sum of the parts is known. For example, you can split a particle with spin of zero into two particles that necessarily will have opposite spins so that their sum is zero.

In 1935, Albert Einstein, Boris Podolsky and Nathan Rosen published a paper that describes a thought experiment designed to illustrate a seeming absurdity of quantum entanglement that challenged a foundational law of the universe.

A simplified version of this thought experiment, attributed to David Bohm, considers the decay of a particle called the pi meson. When this particle decays, it produces an electron and a positron that have opposite spin and are moving away from each other. Therefore, if the electron spin is measured to be up, then the measured spin of the positron could only be down, and vice versa. This is true even if the particles are billions of miles apart.

This would be fine if the measurement of the electron spin were always up and the measured spin of the positron were always down. But because of quantum mechanics, the spin of each particle is both part up and part down until it is measured. Only when the measurement occurs does the quantum state of the spin "collapse" into either up or down—instantaneously collapsing the other particle into the opposite spin. This seems to suggest that the particles communicate with each other through some means that moves faster than the speed of light. But according to the laws of physics, nothing can travel faster than the speed of light. Surely the measured state of one particle cannot instantaneously determine the state of another particle at the far end of the universe?

Physicists, including Einstein, proposed a number of alternative interpretations of quantum entanglement in the 1930s. They theorized there was some unknown property—dubbed hidden variables—that determined the state of a particle before measurement. But at the time, physicists did not have the technology nor a definition of a clear measurement that could test whether quantum theory needed to be modified to include hidden variables.

Disproving a theory

It took until the 1960s before there were any clues to an answer. John Bell, a brilliant Irish physicist who did not live to receive the Nobel Prize, devised a scheme to test whether the notion of hidden variables made sense.

Bell produced an equation now known as Bell's inequality that is always correct—and only correct—for hidden variable theories, and not always for quantum mechanics. Thus, if Bell's equation was found not to be satisfied in a real-world experiment, local hidden variable theories can be ruled out as an explanation for quantum entanglement.

The experiments of the 2022 Nobel laureates, particularly those of Alain Aspect, were the first tests of the Bell inequality. The experiments used entangled photons, rather than pairs of an electron and a positron, as in many thought experiments. The results conclusively ruled out the existence of hidden variables, a mysterious attribute that would predetermine the states of entangled particles. Collectively, these and many follow-up experiments have vindicated quantum mechanics. Objects can be correlated over large distances in ways that physics before quantum mechanics can not explain.

Importantly, there is also no conflict with special relativity, which forbids faster-than-light communication. The fact that measurements over vast distances are correlated does not imply that information is transmitted between the particles. Two parties far apart performing measurements on entangled particles cannot use the phenomenon to pass along information faster than the speed of light.

Today, physicists continue to research quantum entanglement and investigate potential practical applications. Although quantum mechanics can predict the probability of a measurement with incredible accuracy, many researchers remain skeptical that it provides a complete description of reality. One thing is certain, though. Much remains to be said about the mysterious world of quantum mechanics.Quantum entanglement: the 'spooky' science behind physics Nobel

Provided by The Conversation 

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 

Op-Ed: The universe is just a thought, says new theory — Or maybe not BY PAUL WALLIS     DEC 25, 2020 IN SCIENCE Sydney - If the idea that the universe was a big computer simulation was about the equivalent of science fiction B movie, this is the mystic version - The universe simulates itself for information and meaning. Do tell. This idea is promoting itself quite nicely. It’s based on a version of quantum mechanics. So far it has all the pizazz of a quaint new terminology (“panconsciousness”, “panpsychism”, “strange loops”, “not physically there”, etc., and a certain smugness which looks pretty damn lazy to me. If you’ve never read anything in your life, this would be mindblowing. If you have, it’s anything but. The key thing is that “everything is information, expressed as thought.” On that basis, humanity’s claims to existence are in question, as the theory goes on to prove to itself. The universe is supposed to be a self-sustaining mental process, with subconscious micro routines, pure thought, and no advanced beings running the equivalent of a game program. It could even be the past rebooted by future people. Wow, eh? No. It’s bordering on religion, almost psycho-creationism. It’s not exactly a new take on anything much. Anything can be dogmatized into a self-fulfilling prophecy system. “There are carrots; therefore there will be more carrots, because that’s what the system predicts,” aka “God makes carrots.” Never mind the fact that carrots don’t need a system or a theory to reproduce more carrots. They’re not likely to do much else, are they? Ask any vegetable grower how theoretical carrots are. Remarkably few carrots go to church, either. Even evolution is roped in to this remarkably not-very-new theory as “experimentation” by this universal quasi-consciousness. That’s very old science fiction. It goes back to at least Olaf Stapledon’s books circa the 1930s. All you need is a reality, you dumb bastards Quantum physics, which is interesting, unlike this plodding series of self-supporting justifications, is also involved. Quantum physics, if nothing else, is efficient. It works. Quantum reality, in fact, creates its own loops. Quantum entanglement, one of the most significant discoveries of the last century or so, is a case in point. The point being - Everything can have a direct relationship over vast distances, regardless of space and time constraints. Imagine Jewel on a vast scale. Can thought, on whatever level an on whatever scope, manipulate quantum reality? Why not? The human brain generates enough energy to have subatomic let alone quantum particles rattling around all over the place. A universal panconsciousness, or some equivalent, wouldn’t have much trouble doing that either. This is where plausibility meets an obstacle called reality. Horribly (and remarkably ineptly) defined as reality is, you need a medium like existence for all this to work efficiently on any level. In this theory, thought stands in for reality. …Or does it? You have a monoculture of thought creating realities for itself? What about the reality in which this universal mind exists? Can it be one omnipresent thing? If so, where did it come from, as every child quite rightly asks? A reality is a set of applicable integrated functions. (A definition in progress, there.) However, without functionality you don’t have a reality in a functional form. A “self-actualizing” universe could be said to be a tautology – it exists because it exists. How helpful. Particularly to a theory which needs way more legs than this one has. A simulated existence also has a few holes in it. Simulated in relation to what? An underlying existence? An arbitrary existence? This theory has to presuppose the existence of way too many things. Assuming it is mentally possible to create an existence, and many ancient scripts say it is, how do these mental creations fit in with an underlying existence? Not too well, at this point. The properties of the observed universe indicate a lot of things that go boom, much quasi-chaotic behaviour, etc. …And some pretty iffy parameters for what’s doing what, when and where. Superimposed on this almost-slandered reality are things like entropy, cosmic attractors, black holes, and other consistent, if irritating, things rightly or wrongly based on observation. Does this universal panconsciousness have nothing better to do? Consciousness is systemic, systematic, and pretty efficient overall in basic functions. Highter thought is more demanding and often far more complex This state of existence, the electromagnetic circus, doesn’t seem too focused on much more than physical processes. Panpsychism, which links everything to thought, is truly ancient. It goes way back in recorded history. Bigger thinking, like the Tao, start with the premise that the entire process is indescribable. The theory that the universe simulates itself seems more than a little redundant on that basis. Is the universe thinking about what it’s going to do next, before it breaks into showbiz? Chat show opportunities? Blecch. How much of this absolutely requires a universal consciousness to exist? None of it. Basic physics seem to work OK without a dogma attached to each electron. Even if you assume a mind is able to create its own universe, (and there’s precious little reason to believe it can’t or doesn’t at the slightest excuse), so what? Must we have an overarching theory to explain that? This theory also degenerates into some pretty tacky sophisms – “How do you know you’re not dreaming?”, and other paraphrased quotes. “Am I a butterfly dreaming I’m a man”, etc. “Minds that do not require matter”, and other open door non-statements are also included in this delightful package. Do better than that, guys. Very old, and much better expressed centuries ago. This go-nowhere theory achieves its purpose of reiterating millennia of prior thought. It just happens to do so very unimpressively. The ghost of von Daniken is obviously looking for company, so be very very quiet if you’re hunting rabbits.

Read more: http://www.digitaljournal.com/tech-and-science/science/op-ed-the-universe-is-just-a-thought-says-new-theory-or-maybe-not/article/583084#ixzz6i5YXgqeT

UK Scientists make major breakthrough in developing practical quantum computers that can solve big challenges of our time

Universal of Sussex and Universal Quantum scientists have, for the first time, connected quantum microchips together, like a jigsaw puzzle, to make powerful quantum computers and with record breaking connection speed and accuracy

Peer-Reviewed Publication

UNIVERSITY OF SUSSEX

 

IMAGE: GRAPHIC SHOWING TWO QUANTUM COMPUTER MODULES BEING ALIGNED SO THAT ATOMS CAN TRANSFER FROM ONE QUANTUM COMPUTER MICROCHIP TO ANOTHER view more 

CREDIT: UNIVERSITY OF SUSSEX

Researchers from the University of Sussex and Universal Quantum have demonstrated for the first time that quantum bits (qubits) can directly transfer between quantum computer microchips and demonstrated this with record-breaking speed and accuracy.  This breakthrough resolves a major challenge in building quantum computers large and powerful enough to tackle complex problems that are of critical importance to society.

Today, quantum computers operate on the 100-qubit scale. Experts anticipate millions of qubits are required to solve important problems that are out of reach of today’s most powerful supercomputers [1, 2]. There is a global quantum race to develop quantum computers that can help in many important societal challenges from drug discovery to making fertilizer production more energy efficient and solving important problems in nearly every industry, ranging from aeronautics to the financial sector.

In the research paper, published today (from 10:00 GMT, Wednesday 8 February 2023) in Nature Communications, the scientists demonstrate how they have used a new and powerful technique, which they dub ‘UQ Connect’, to use electric field links to enable qubits to move from one quantum computing microchip module to another with unprecedented speed and precision. This allows chips to slot together like a jigsaw puzzle to make a more powerful quantum computer.

The University of Sussex and Universal Quantum team were successful in transporting the qubits with a 99.999993% success rate and a connection rate of 2424/s, both numbers are world records and orders of magnitude better than previous solutions.

Professor Winfried Hensinger, Professor of Quantum Technologies at the University of Sussex and Chief Scientist and Co-founder at Universal Quantum said: “As quantum computers grow, we will eventually be constrained by the size of the microchip, which limits the number of quantum bits such a chip can accommodate. As such, we knew a modular approach was key to make quantum computers powerful enough to solve step-changing industry problems. In demonstrating that we can connect two quantum computing chips – a bit like a jigsaw puzzle – and, crucially, that it works so well, we unlock the potential to scale-up by connecting hundreds or even thousands of quantum computing microchips.”

While linking the modules at world-record speed, the scientists also verified that the ‘strange’ quantum nature of the qubit remains untouched during transport, for example, that the qubit can be both 0 and 1 at the same time.

Dr Sebastian Weidt, CEO and Co-founder of Universal Quantum, and Senior Lecturer in Quantum Technologies at the University of Sussex said: “Our relentless focus is on providing people with a tool that will enable them to revolutionise their field of work. The Universal Quantum and University of Sussex teams have done something truly incredible here that will help make our vision a reality. These exciting results show the remarkable potential of Universal Quantum’s quantum computers to become powerful enough to unlock the many lifechanging applications of quantum computing.”

Universal Quantum has just been awarded €67 million from the German Aerospace Center (DLR) to build two quantum computers where they will deploy this technology as part of the contract. The University of Sussex spin-out was also recently named as one of the 2022 Institute of Physics award winners in the Business Start-up category.

Weidt added: “The DLR contract was likely one of the largest government quantum computing contracts ever handed out to a single company. This is a huge validation of our technology. Universal Quantum is now working hard to deploy this technology in our upcoming commercial machines.”

Dr Mariam Akhtar led the research during her time as Research Fellow at the University of Sussex and Quantum Advisor at Universal Quantum. She said: “The team has demonstrated fast and coherent ion transfer using quantum matter links. This experiment validates the unique architecture that Universal Quantum has been developing – providing an exciting route towards truly large-scale quantum computing.”

Professor Sasha Roseneil, Vice-Chancellor of the University of Sussex, said: “It’s fantastic to see that the inspired work of the University of Sussex and Universal Quantum physicists has resulted in this phenomenal breakthrough, taking us a significant step closer to a quantum computer that will be of real societal use. These computers are set to have boundless applications – from improving the development of medicines, creating new materials, to maybe even unlocking solutions to the climate crisis. The University of Sussex is investing significantly in quantum computing to support our bold ambition to host the world’s most powerful quantum computers and create change that has the potential to positively impact so many people across the world. And with teams spanning the spectrum of quantum computing and technology research, the University of Sussex has both a breadth and a depth of expertise in this. We are still growing our research and teaching in this area, with plans for new teaching programmes, and new appointments.”

Professor Keith Jones, Interim Provost and Pro-Vice Chancellor for Research and Enterprise at the University of Sussex, said of the development: “This is a very exciting finding from our University of Sussex physicists and Universal Quantum. It proves the value and dynamism of this University of Sussex spin-out company, whose work is grounded in rigorous and world-leading academic research. Quantum computers will be pivotal in helping to solve some of the most pressing global issues. We're delighted that Sussex academics are delivering research that offers hope in realising the positive potential of next-generation quantum technology in crucial areas such as sustainability, drug development, and cybersecurity.”  

-ENDS-

NOTES TO EDITOR

[1] Webber, M., et. al. AVS Quantum Sci. 4, 013801 (2022)

[2] Lekitsch, B., et al., Science Advances, 3(2), 1–12 (2017)

MEDIA CONTACTS

University of Sussex

Alice Ingall: a.r.ingall@sussex.ac.uk / 07899096299
Anna Ford: a.ford@sussex.ac.uk / press@sussex.ac.uk

Universal Quantum

Gemma Church: gemma@universalquantum.com / media@universalquantum.com /+44 7967 565 080

ABOUT THE UNIVERSITY OF SUSSEX

For over 60 years the aim of our courses, research, culture and campus has been to stimulate, excite and challenge. So, from scientific discovery to global policy, from student welfare to career development, the University of Sussex innovates and takes a lead. And today, in every part of society and across the world, you will find someone from the University of Sussex making an original and valuable contribution. Visit www.sussex.ac.uk     

ABOUT UNIVERSAL QUANTUM

Universal Quantum builds quantum computers that will one day help humanity solve some of its most pressing problems in areas such as drug discovery and climate change as well as shed light on its biggest scientific mysteries. To achieve this, quantum computers with millions of qubits are required, which is often described as one of the biggest technology challenges of our time.

Universal Quantum has developed a unique modular architecture to solve exactly that challenge. Its trapped ion-based electronic quantum computing modules are manufactured using available silicon technology. Individual modules are connected using its record-breaking UQ Connect technology to form an architecture that can scale to millions of qubits.

With 15+ years of quantum computing experience, Universal Quantum is a spin-out from the University of Sussex, founded by Dr Sebastian Weidt and Professor Winfried Hensinger in 2018 and supported by leading investors. Visit www.universalquantum.com
 

University of Sussex and Universal Quantum scientists, Professor Winfried Hensinger and Dr Sebastian Weidt in University of Sussex quantum computing labs.

Quantum computer setup at the University of Sussex with two quantum computer microchips where quantum bits are transferred from one microchip to another with record speed.

CREDIT

University of Sussex

---

JOURNAL

Nature Communications

DOI

10.1038/s41467-022-35285-3 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

A high-fidelity quantum matter-link between ion-trap microchip modules

ARTICLE PUBLICATION DATE

8-Feb-2023

COI STATEMENT

The authors declare the following competing interests: M.A., F.B., F.R.L.-G., S.W. and W.K.H. are associated and/or hold shares with quantum computing company Universal Quantum Ltd. that will make use of some of the findings of this article in the quantum computers they develop. The remaining authors declare no other competing interests.

 

New study uses machine learning to bridge the reality gap in quantum devices

Peer-Reviewed Publication

UNIVERSITY OF OXFORD

FOR IMMEDIATE RELEASE TUESDAY 9 JANUARY 2024

New study uses machine learning to bridge the reality gap in quantum devices

A study led by the University of Oxford has used the power of machine learning to overcome a key challenge affecting quantum devices. For the first time, the findings reveal a way to close the ‘reality gap’: the difference between predicted and observed behaviour from quantum devices. The results have been published in Physical Review X.

Quantum computing could supercharge a wealth of applications, from climate modelling and financial forecasting, to drug discovery and artificial intelligence. But this will require effective ways to scale and combine individual quantum devices (also called qubits). A major barrier against this is inherent variability: where even apparently identical units exhibit different behaviours.

Functional variability is presumed to be caused by nanoscale imperfections in the materials that quantum devices are made from. Since there is no way to measure these directly, this internal disorder cannot be captured in simulations, leading to the gap in predicted and observed outcomes.

To address this, the research group used a “physics-informed” machine learning approach to infer these disorder characteristics indirectly. This was based on how the internal disorder affected the flow of electrons through the device.

Lead researcher Associate Professor Natalia Ares (Department of Engineering Science, University of Oxford) said: ‘As an analogy, when we play “crazy golf” the ball may enter a tunnel and exit with a speed or direction that doesn’t match our predictions. But with a few more shots, a crazy golf simulator, and some machine learning, we might get better at predicting the ball’s movements and narrow the reality gap.’

The researchers measured the output current for different voltage settings across an individual quantum dot device. The data was input into a simulation which calculated the difference between the measured current with the theoretical current if no internal disorder was present. By measuring the current at many different voltage settings, the simulation was constrained to find an arrangement of internal disorder that could explain the measurements at all voltage settings. This approach used a combination of mathematical and statistical approaches coupled with deep learning.

Associate Professor Ares added: ‘In the crazy golf analogy, it would be equivalent to placing a series of sensors along the tunnel, so that we could take measurements of the ball’s speed at different points. Although we still can’t see inside the tunnel, we can use the data to inform better predictions of how the ball will behave when we take the shot.’

Not only did the new model find suitable internal disorder profiles to describe the measured current values, it was also able to accurately predict voltage settings required for specific device operating regimes.

Crucially, the model provides a new method to quantify the variability between quantum devices. This could enable more accurate predictions of how devices will perform, and also help to engineer optimum materials for quantum devices. It could inform compensation approaches to mitigate the unwanted effects of material imperfections in quantum devices.

Co-author David Craig, a PhD student at the Department of Materials, University of Oxford, added, ‘Similar to how we cannot observe black holes directly but we infer their presence from their effect on surrounding matter, we have used simple measurements as a proxy for the internal variability of nanoscale quantum devices. Although the real device still has greater complexity than the model can capture, our study has demonstrated the utility of using physics-aware machine learning to narrow the reality gap.’

Notes to editors:

For media enquiries and interview requests, contact Dr Natalia Ares: natalia.ares@eng.ox.ac.uk

The study ‘Bridging the reality gap in quantum devices with physics-aware machine learning’ has been published in Physical Review X: https://journals.aps.org/prx/abstract/10.1103/PhysRevX.14.011001

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JOURNAL

Physical Review X

DOI

10.1103/PhysRevX.14.011001 

ARTICLE TITLE

Bridging the Reality Gap in Quantum Devices with Physics-Aware Machine Learning