5 Oct 2022

Physics Nobel rewards 'spooky science' of entanglement

3:32 pm on 5 October 2022
Austrian physicist Anton Zeilinger smiles during a press conference on October 4, 2022 at the University of Vienna, after he was awarded with the 2022 Nobel Prize in Physics. - The Royal Swedish Academy of Sciences has decided on October 4, 2022 to award the 2022 Nobel Prize in Physics to Anton Zeilinger, among two other quantum mechanics physicians. (Photo by JOE KLAMAR / AFP)

Austrian physicist Anton Zeilinger smiles during a press conference on October 4, 2022 at the University of Vienna, after he was awarded with the 2022 Nobel Prize in Physics. Photo: JOE KLAMAR / AFP

By Jonathan Amos for the BBC

This year's Nobel Prize in Physics rewards research into quantum mechanics - the science that describes nature at the smallest scales.

The award goes to Frenchman Alain Aspect, American John Clauser and Austrian Anton Zeilinger.

Their work should pave the way to a new generation of powerful computers and telecommunications systems that are impossible to break into.

The men will share prize money of 10 million Swedish krona (NZ$1.5m).

This year's three laureates conducted ground-breaking experiments using entangled quantum states, where two sub-atomic particles behave like a single unit even when they are separated.

"Quantum information science is a vibrant and rapidly developing field," said Eva Olsson, a member of the Nobel Committee for Physics.

"It has broad and potential implications in areas such as secure information transfer, quantum computing, and sensing technology."

Alain Aspect, 75, is affiliated to the Université Paris-Saclay and École Polytechnique, Palaiseau. John Clauser, 79, runs his own company in California. Anton Zeilinger, 77, is attached to the University of Vienna.

The same three men won the Wolf Prize together in 2010.

WALNUT CREEK, CALIFORNIA - OCTOBER 04: Research physicist John F. Clauser poses for a photo at his home on October 04, 2022 in Walnut Creek, California. John F. Clauser jointly won a Nobel Prize in physics with two other scientists, Alain Aspect of France, and Anton Zeilinger of Austria, for their work on quantum information science. The scientists were cited for discovering the way that particles known as photons can be linked with each other even when they are separated by large distances.   Justin Sullivan/Getty Images/AFP (Photo by JUSTIN SULLIVAN / GETTY IMAGES NORTH AMERICA / Getty Images via AFP)

Research physicist John F. Clauser poses for a photo at his home on 4 October in Walnut Creek, California. Photo: JUSTIN SULLIVAN / AFP

Anton Zeilinger got an early morning call to tell him he'd won. "I'm still kind of shocked, but it's a very positive shock," he said.

Quantum mechanics describes the behaviour of sub-atomic particles. It's a field that was opened up in the early 20th Century. And it's in a particular aspect of this science that Tuesday's laureates made their name.

It concerns something called "entanglement" in which two or more quantum particles - usually photons, the particles of light - can be strongly connected when very far apart even though they are not physically linked.

Their shared state might be their energy or their spin. It's a strange phenomenon that Albert Einstein called "spooky action at a distance".

The theoretical underpinning was developed in the 1960s by Northern Irish physicist John Stewart Bell. But it was Aspect, Clauser and Zeilinger who then conducted the experiments to show the phenomenon was real and could have practical uses.

"I was always interested in quantum mechanics from the very first moments when I read about it," Prof Zeilinger told BBC News. "And I actually was struck by some of the theoretical predictions because they did not fit the usual intuitions that one might have."

Two areas of entanglement research are garnering a lot of attention today. One is in quantum computers which promise a leap in the ability to solve complex problems. And the other is in encryption, the secure encoding of information. Exploiting entanglement will make it impossible for a third party to eavesdrop on private communications.

"This is useful for military and banking, etc, in secure communications," John Clauser said. "The biggest application to my knowledge is the Chinese who launched a satellite several years ago that they use for secure communications over thousands of kilometres."

Commenting, Prof Tim Spiller from York University, UK, said the new laureates were worthy winners who had helped to open up an exciting future.

"Quantum technologies have been pursued significantly in the UK and in many other countries worldwide for the last 10 years. We've known about entanglement for rather longer than that, but the investment has been made over the last 10 years to actually really start to exploit this. And there are now one or two commercial products emerging that you can buy that use various aspects of this quantum feature, and we expect there will be many more in the future," he told BBC News.

The Physics Nobel in 2021 was given to three researchers who advanced our understanding of complex systems - in particular, Earth's climate.

On Monday, the Nobel committee gave the Physiology or Medicine prize to Sweden's Svante Paabo for his work on human evolution.

- BBC