Quantum weirdness testing and its potential real-world applications have been awarded the 2022 Nobel Prize in Physics.
At some level, we are all subject to quantum rules that even Albert Einstein struggled to accept. For the most part, these rules play out behind the scenes in the transistors that make up computer chips, lasers, and even in the chemistry of atoms and molecules in the materials around us. The applications that stem from this year’s Nobel Prize take advantage of larger-scale quantum features. They include absolutely secure communications and quantum computers that could possibly solve problems that no conventional computer imaginable could solve for the lifetime of the universe.
This year’s prize is shared between three physicists. Alain Aspect and John Clauser have confirmed that the rules of quantum mechanics, as strange and hard to believe as they are, really rule the world, while Anton Zeilinger has taken advantage of strange quantum behaviors to develop rudimentary applications that no conventional technology can match. Each winner will take home a third of the prize money, which amounts to 10 million Swedish kronor, worth approximately $915,000 as of October 4.
“Today we pay tribute to three physicists whose pioneering experiments have shown us that strange world of tangle …is not just the micro-world of atoms, and certainly not the virtual world of science fiction or mysticism, but it is the real world we all live in,” said Thors Hans Hansson, member of the Nobel Committee for Physics, at a press conference announcing the prize on October 4 at the Royal Swedish Academy of Sciences (SN: 05/11/10).
“It was certainly very exciting to learn more about the three winners,” says physicist Jerry Chow of IBM Quantum in Yorktown Heights, NY “Aspect, Zeilinger and Clauser – they are all very, very well known in our community quantum, and their work is something that has really been a big part of many people’s research efforts over many years.
Aspect, from the University of Paris-Saclay and the École Polytechnique in France, and Clauser, who now runs a company in California, have shown that there is no secret return channels of communication that explain how two particles can exist as a single entity, even though they are far apart (SN: 12/29/14).
Experiments by Zeilinger of the University of Vienna that build on this quantum behavior include demonstrations of communications, absolutely secure encryption, and crucial components for quantum computers. He pioneered another largely misunderstood application: quantum teleportation. Unlike the teleportation of people and objects in science fiction, the effect involves the perfect transmission of information about a quantum object from one location to another.
“I’ve always been interested in quantum mechanics from the first moment I read about it,” Zeilinger said by phone at the press conference announcing the award. “I was actually struck by some of the theoretical predictions, because they didn’t align with the usual hunches one might have.”
The discovery of quantum behavior that governs the world on a small scale, such as the movement of an electron around an atom, revolutionized physics in the early 20th century. Many leading scientists, including Einstein, recognized that quantum theories worked, but argued that they couldn’t be the true description of the world because it was, at best, a matter of calculating the probabilities of something happening (SN: 01/12/22). For Einstein, this meant that there was hidden information that experiments were too crude to uncover.
Others believed that quantum behavior, oddly pejoratively called, though difficult to understand, had no secret way of transmitting information. It was largely a matter of opinion and debate until physicist John Bell proposed a test in the 1960s prove that there were no hidden channels of communication between quantum objects (SN: 12/29/14). At the time, it was not clear that an experiment to perform the test was possible.
Clauser was the first to develop practical experience to confirm Bell’s test, although there remained gaps which his experience could not verify and which left room for doubt. (His interest in science developed early. In 1959 and 1960, Clauser participated in the National Science Fairnow known as the International Science and Engineering Fair (SN: 05/23/59). The fair is managed by the Society for Science, which publishes Scientific News.)
Aspect pushed the idea further to eliminate any possibility that quantum mechanics has hidden foundations of classical physics (SN: 1/11/86). Clauser and Aspect’s experiments involved creating pairs of photons that were entangled, meaning they were essentially a single object. As the photons moved in different directions, they remained entangled. That is, they continue to exist as a single, extended object. Measuring the characteristics of one instantly reveals the characteristics of the other, regardless of their distance.
Entanglement is a delicate and difficult situation to maintain, but the results of Clauser and Aspect’s experiments show that quantum effects cannot be explained with hidden variables that would be signs of non-quantum foundations.
For Chow, the importance of this research is twofold. “There really is an element of demonstration, from a philosophical point of view, that quantum mechanics is real,” he says. “But then, from a more practical point of view…this same beautiful theory of quantum mechanics gives a different set of rules by which information is processed.” This, in turn, opens up new avenues for next-generation technologies like quantum computers and communications (SN: 03/12/20).
Zeilinger’s experiments take advantage of entanglement to achieve feats that would not be possible without the effects confirmed by Clauser and Aspect. He extended the experiences of the laboratory at intercontinental distancesopening up the possibility of practical use of entanglement (SN: 05/31/12). Because interaction with one of a pair of entangled particles affects the other, they can become key components in secure communications and encryption. An alien trying to eavesdrop on a Quantum Communique would be revealed because they would break through the entanglement while spying.
Quantum computers that rely on entangled particles have also become a subject of active research. Instead of the ones and zeros of conventional computers, quantum computers encode information and perform calculations that are mixtures of ones and zeros. In theory, they can perform calculations that no digital computer could ever match. Zeilinger quantum teleportation experiments provide a pathway to transfer the information that these quantum computers rely on (SN: 01/17/98).
“This [award] is a very nice and positive surprise for me,” says Nicolas Gisin, a physicist at the University of Geneva in Switzerland. “This award is very well deserved, but comes a little late. Most of this work has been done in the [1970s and 1980s]but the Nobel committee has been very slow and is now rushing after the quantum technologies boom.
This boom is happening globally, says Gisin. “In the United States, Europe and China, billions – literally billions of dollars are being poured into this. So that changes completely,” he says. “Instead of having a few pioneering individuals in the field, we now have very large crowds of physicists and engineers working together.”
Although some of the most esoteric quantum applications are in their infancy, the experiments of Clauser, Aspect and Zeilinger introduce quantum mechanics and its strange implications into the macroscopic world. Their contributions validate some of the key, once-controversial ideas of quantum mechanics and promise new applications that may one day be commonplace in everyday life, in ways that even Einstein couldn’t deny.
Maria Temming contributed reporting for this story.