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Three physicists win the Nobel for work on quantum entanglement
© Provided by Inverse“Is nature a trickster?” On Tuesday, the Nobel Committee posed this question regarding what may be nature’s slightest sleight of hand: quantum mechanics.
Quantum mechanics is an area of physics that deals with all things subatomic. This field throws a wrench into pre-existing classical physics, which gave us the Standard Model that explains three of the universe’s four forces and identifies all known subatomic particles. Quantum mechanics endeavors to predict where a particle will be at any given moment. Simple stuff.
There’s one especially tricky aspect of quantum mechanics known as entanglement. This phenomenon occurs when two particles, even if they’re far from each other, act in unison. Effects on one particle will also impact its pair. Even though they’re separate, they operate as a single unit. Einstein described this behavior as “spooky action at a distance.”
This year, Alain Aspect, John Clauser, and Anton Zeilinger share the Nobel Prize in Physics for their respective contributions to quantum mechanics, demonstrating not only its theoretical capacities but also showing that photons in entangled states are all around us.
How it all started — Irish physicist John Stewart Bell published a 1964 paper developing a mathematical inequality known as Bell’s inequality. According to this principle, if hidden variables exist within the entangled pair, then the correlation between results of a large number of measurements will always remain within certain boundaries.
Quantum mechanics, however, says that some kind of experiment will violate Bell’s inequality. This violation implicates a stronger correlation than thought possible between two particles.
How this changed science as we know it — American John Clauser created a practical experiment from Bell’s theory. He’s the one who found the experiment that violated Bell’s inequality while supporting quantum mechanics, meaning that a theory using hidden variables can’t replace quantum mechanics.
Alain Aspect of France further built on this finding, closing a loophole in Clauser’s finding. He modified the experiment’s measurement settings after an entangled pair had launched from its source. The existing setting then couldn’t affect the resulting measurements.
Austrian Anton Zeilinger toyed with these entangled quantum states. His research depicted a principle called quantum teleportation, in which one particle can move quantum states over a distance.
Why these discoveries are important — A goal of quantum mechanics, the Nobel Committee says, is to build a quantum network. They describe this network as a series of nodes that use quantum entanglement to communicate. This network has applications in encryption and quantum computing, which can synthesize astronomical amounts of information.
Understanding entanglement is key since it’s what ties this network together. However, entanglement is brittle and comes apart in optical fibers meant to transmit it.
Recipient Anton Zeilinger said on a call when the award was publicly announced that the next generation will be the ones to build on the remaining questions. "This prize is an encouragement to young people," he said. He also acknowledged the more than 100 students he had worked with to even get this far. While physicists have made strides in this area, there's still a long way to go.
Nobel Prize for Physics given to scientists who ‘opened doors to another world’ with quantum discoveries
Nobel Physics (AFP or licensors)
The Nobel Prize in Physics has been given to three scientists who “opened doors to another world”, according to the committee.
The three were all recognised for their work on quantum entanglement, a “totally crazy” field once of philosophical musings that is developing into somewhat promising real-world use, such as secure encryption of information.
A member of the committee, Eva Olson, said that the prize recognised both the broad implications of their work as well as the deep philosophical changes it had brought about.
“It has broad and potential implications in areas such as secure information transfer, quantum computing and sensing technology.”
“Its origin can be traced to that of quantum mechanics,” she said.
“Its predictions have opened doors to another world, and it has also shaken the very foundations of how we interpret measurements.”
Frenchman Alain Aspect, American John F. Clauser and Austrian Anton Zeilinger were cited by the Royal Swedish Academy of Sciences for discovering the way that unseen particles, such as photons, can be linked, or “entangled,” with each other even when they are separated by large distances.
It all goes back to a feature of the universe that even baffled Albert Einstein and connects matter and light in a tangled, chaotic way.
Bits of information or matter that used to be next to each other even though they are now separated have a connection or relationship — something that can conceivably help encrypt information or even teleport. A Chinese satellite now demonstrates this and potentially lightning fast quantum computers, still at the small and not quite useful stage, also rely on this entanglement. Others are even hoping to use it in superconducting material.
“It’s so weird,” Aspect said of entanglement in a telephone call with the Nobel committee. “I am accepting in my mental images something which is totally crazy.”
Yet the trio’s experiments showed it happen in real life.
“Why this happens I haven’t the foggiest,” Clauser told The Associated Press during a Zoom interview in which he got the official call from the Swedish Academy several hours after friends and media informed him of his award. “I have no understanding of how it works but entanglement appears to be very real.”
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His fellow winners also said they can’t explain the how and why behind this effect. But each did ever more intricate experiments that prove it just is.
Clauser, 79, was awarded his prize for a 1972 experiment, cobbled together with scavenged equipment, that helped settle a famous debate about quantum mechanics between Einstein and famed physicist Niels Bohr. Einstein described “a spooky action at a distance” that he thought would eventually be disproved.
“I was betting on Einstein,” Clauser said. “But unfortunately I was wrong and Einstein was wrong and Bohr was right.”
Aspect said Einstein may have been technically wrong, but deserves huge credit for raising the right question that led to experiments proving quantum entanglement. “Most people would assume that nature is made out of stuff distributed throughout space and time,” said Clauser, who while a high school student in the 1950s built a video game on a vacuum tube computer. “And that appears not to be the case.” What the work shows is “parts of the universe — even those at great distances from each other — are connected,” said Johns Hopkins physicist N. Peter Armitage. “This is something so unintuitive and something so at odds with how we feel the world ‘should’ be.” This hard-to-understand field started with thought experiments. But what in one sense is philosophical musings about the universe also holds hope for more secure and faster computers all based on entangled photons and matter that still interact no matter how distant. “With my first experiments I was sometimes asked by the press what they were good for,” Zeilinger, 77, told reporters in Vienna. “And I said with pride: ‘It’s good for nothing. I’m doing this purely out of curiosity.”’ In quantum entanglement, establishing common information between two photons not near each other “allows us to do things like secret communication, in ways which weren’t possible to do before,” said David Haviland, chair of the Nobel Committee for Physics. Quantum information “has broad and potential implications in areas such as secure information transfer, quantum computing and sensing technology,” said Eva Olsson, a member of the Nobel committee. “Its predictions have opened doors to another world, and it has also shaken the very foundations of how we interpret measurements.”
The kind of secure communication used by China’s Micius satellite — as well as by some banks — is a “success story of quantum entanglement,” said Harun Siljak of Trinity College Dublin. By using one entangled particle to create an encryption key, it ensures that only the person with the other entangled particle can decode the message and “the secret shared between these two sides is a proper secret,” Siljak said.
While quantum entanglement is “incredibly cool” security technologist Bruce Schneier, who teaches at Harvard, said it is fortifying an already secure part of information technology where other areas, including human factors and software are more of a problem. He likened it to installing a side door with 25 locks on an otherwise insecure house.
At a news conference, Aspect said real-world applications like the satellite were “fantastic.”
“I think we have progress toward quantum computing. I would not say that we are close,” the 75-year-old physicist said. “I don’t know if I will see it in my life. But I am an old man.”
Speaking by phone to a news conference after the announcement, the University of Vienna-based Zeilinger said he was “still kind of shocked” at hearing he had received the award.
Clauser, Aspect and Zeilinger have figured in Nobel speculation for more than a decade. In 2010 they won the Wolf Prize in Israel, seen as a possible precursor to the Nobel.
The Nobel committee said Clauser developed quantum theories first put forward in the 1960s into a practical experiment. Aspect was able to close a loophole in those theories, while Zeilinger demonstrated a phenomenon called quantum teleportation that effectively allows information to be transmitted over distances.
“Using entanglement you can transfer all the information which is carried by an object over to some other place where the object is, so to speak, reconstituted,” Zeilinger said. He added that this only works for tiny particles.
“It is not like in the Star Trek films (where one is) transporting something, certainly not the person, over some distance,” he said.
A week of Nobel Prize announcements kicked off Monday with Swedish scientist Svante Paabo receiving the award in medicine Monday for unlocking secrets of Neanderthal DNA that provided key insights into our immune system.
Chemistry is on Wednesday and literature on Thursday. The Nobel Peace Prize will be announced Friday and the economics award on Oct. 10.
The prizes carry a cash award of 10 million Swedish kronor (nearly $900,000) and will be handed out on Dec. 10. The money comes from a bequest left by the prize’s creator, Swedish dynamite inventor Alfred Nobel, who died in 1895.
Additional reporting by agencies
Sleuths of 'spooky' quantum science win Nobel physics prize
STOCKHOLM, Oct 4 (Reuters) - Scientists Alain Aspect, John Clauser and Anton Zeilinger won the 2022 Nobel Prize in Physics for experiments in quantum mechanics that laid the groundwork for rapidly-developing new applications in computing and cryptography.
"Their results have cleared the way for new technology based upon quantum information," the Royal Swedish Academy of Sciences said of the laureates -- Aspect, who is French, Clauser, an American and Zeilinger, an Austrian.
The scientists all conducted experiments into quantum entanglement, where two particles are linked regardless of the space between them, a field that unsettled Albert Einstein himself, who once referred to it in a letter as "spooky action at a distance".
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"I'm very happy ... I first started this work back in 1969 and I'm happy to still be alive to be able get the prize," Clauser, 79, told Reuters by phone from his home in Walnut Creek, California.
Clauser, who worked at institutions such as Lawrence Berkeley National Laboratory and the University of California, Berkeley, during his career, said he had witnessed his initial work snowball into much larger experiments.
China's Micius satellite, part of a quantum physics research project, was constructed in part on his findings, he said.
"The configuration of the satellite and the ground station is almost identical to my original experiment. Mine was about 30 feet long, theirs is thousands of kilometers for quantum communication."
Asked to explain his work in layman's terms, he joked he does not understand it himself but added that the interactions it describes permeate almost everything.
"Probably every particle in the universe is entangled with every other particle," Clauser said, chuckling.
NATURE OF REALITYFrench President Emmanuel Macron tweeted his congratulations to the winners, adding "Einstein himself did not believe in quantum entanglement! Today, the promises of quantum computing are based on this phenomenon."
Aspect, professor at Universite Paris-Saclay and Ecole Polytechnique, Palaiseau, near Paris, said he was happy his work had contributed to settling the debate between Einstein, who was sceptical about quantum physics, and Niels Bohr, one of the field's fathers. Both won Nobel physics prizes.
"Quantum physics, which has been fantastic field that has been on the agenda for more than a century, still offers a lot of mysteries to discover," Aspect, 75, told reporters.
Secretary General of the Royal Swedish Academy of Sciences Hans Ellegren, Eva Olsson and Thors Hans Hansson, members of the Nobel Committee for Physics announce the winners of the 2022 Nobel Prize in Physics Alain Aspect, John F. Clauser and Anton Zeilinger, during a news conference at The Royal Swedish Academy of Sciences in Stockholm, Sweden, October 4, 2022. TT News Agency/ Jonas Ekstromervia REUTERS
Read More"This prize today anticipates what will be one day be quantum technologies."
Zeilinger, 77, professor emeritus at the University of Vienna, told a news conference by phone after hearing the news that he was "shocked, but very positive."
In an interview after being awarded an honorary doctorate earlier this year, Zeilinger said that protected quantum communication over potentially thousands of kilometres via cables or satellite would soon be on the cards.
"It is quite clear that in the near future we will have quantum communication all over the world," he said at the time.
Quantum physics is the study of matter and energy at a subatomic level involving the smallest building blocks of nature, a realm governed by laws jarring with those of the classical Newtonian physics used in areas such as the motions of celestial objects.
In background material explaining the prize, the academy said the laureates' work involved "the mind-boggling insight that quantum mechanics allows a single quantum system to be divided up into parts that are separated from each other but which still act as a single unit."
"This goes against all the usual ideas about cause and effect and the nature of reality."
PRIZE 'LONG OVERDUE'The laureates explored in ground-breaking experiments how two or more photons, or particles of light, that are "entangled" because they come from the same laser beam, interact even when they are separated far apart from each other.
Sean Carroll, Professor of Natural Philosophy at Johns Hopkins University and author of books on topics such as quantum mechanics, told Reuters the prize for the trio was long overdue.
"Even though the ... experimental techniques that these folks pioneered might not be directly applicable, they're laying the ground work for using quantum entanglement as a technological resource," he said.
The more than century-old prize, worth 10 million Swedish crowns ($902,315), is awarded by the Royal Swedish Academy of Sciences. Physics is the second Nobel to be awarded this week after Swedish geneticist Svante Paabo won the prize for Physiology or Medicine on Monday.
The physics prize has often taken centre stage among the awards, featuring household names of science such as Einstein, Bohr and Max Planck, and rewarding breakthroughs that have reshaped how we see the world.
($1 = 11.0826 Swedish crowns)
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Reporting by Niklas Pollard, Simon Johnson and Johan Ahlander in Stockholm, Jonathan Allen in New York and Ludwig Burger in Frankfurt; additional reporting by Terje Solsvik in Oslo, Anna Ringstrom in Stockholm, Geert De Clercq in Paris, and Marie Mannes in Gdansk; Editing by William Maclean and Nick Zieminski
Our Standards: The Thomson Reuters Trust Principles.
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