Physicist — John Francis Clauser (Pasadena, 1942) is an American physicist, awarded the Nobel Prize in Physics in 2022 together with Alain Aspect and Anton Zeilinger. Trained at Caltech and Columbia University, he devoted himself to the foundations of quantum mechanics at a time when the subject was considered of little academic standing. In the early 1970s he carried out, with Stuart Freedman, one of the first experiments aimed at testing Bell’s inequalities, putting the non-local nature of quantum entanglement to the test against local hidden-variable theories. He also helped formulate the so-called CHSH inequality, a version of Bell’s inequalities suited to real experiments. His work paved the way for the experimental verification of entanglement and the development of quantum information.
Trivia
Clauser recounted that he had initially hoped the experiment would vindicate Einstein against quantum mechanics; the results instead clearly showed the correlations predicted by quantum theory, contradicting his expectations.
Theories and contributions
- CHSH inequality — Experimental form of Bell’s inequalities: for local hidden-variable theories , while quantum mechanics can reach .
- Freedman–Clauser experiment — First experimental test of the violation of Bell’s inequalities using entangled photon pairs (1972), in favour of quantum mechanics.
Featured in chapters
Linked atoms
1 linked atoms.