4. October 2022

4. October 2022

We congratulate very warmly. With Anton Zeilinger the 24^{th} Exner Medal winner wins a Nobel Prize!

From the statement of the Swedish Academy of Sciences:

Alain Aspect, John Clauser and Anton Zeilinger have been awarded the Nobel Prize in Physics 2022 *“for experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science”*

Each of them conducted groundbreaking experiments using entangled quantum states, where two particles behave like a single unit even when they are separated. Their results have cleared the way for new technology based upon quantum information.

The ineffable effects of quantum mechanics are starting to find applications. There is now a large field of research that includes quantum computers, quantum networks and secure quantum encrypted communication.

One key factor in this development is how quantum mechanics allows two or more particles to exist in what is called an entangled state. What happens to one of the particles in an entangled pair determines what happens to the other particle, even if they are far apart.

For a long time, the question was whether the correlation was because the particles in an entangled pair contained hidden variables, instructions that tell them which result they should give in an experiment. In the 1960s, John Stewart Bell developed the mathematical inequality that is named after him. This states that if there are hidden variables, the correlation between the results of a large number of measurements will never exceed a certain value. However, quantum mechanics predicts that a certain type of experiment will violate Bell’s inequality, thus resulting in a stronger correlation than would otherwise be possible.