Anton Zeilinger (German: [ˈanton ˈtsaɪlɪŋɐ]; born 20 May 1945) is an Austrian quantum physicist and Nobel laureate in physics of 2022.

[9][8] In October 2022, he received the Nobel Prize in Physics, jointly with Alain Aspect and John Clauser for their work involving experiments with entangled photons, establishing the violation of Bell inequalities and pioneering quantum information science.

[11] He received a doctorate from the University of Vienna in 1971, with a thesis on "Neutron depolarization measurements on a Dy-single crystal" under Helmut Rauch.

[30] Finally, in 1999, he succeeded in providing the first experimental evidence of entanglement beyond two particles[31] and also the first test of quantum nonlocality for GHZ states.

[35] The experiments of Zeilinger and his group on the distribution of entanglement over large distances began with both free-space and fiber-based quantum communication and teleportation between laboratories located on the different sides of the river Danube.

[36] This was then extended to larger distances across the city of Vienna[37] and over 144 km between two Canary Islands, resulting in a successful demonstration that quantum communication with satellites is feasible.

The source for polarization-entangled photon pairs developed with Paul Kwiat when he was a PostDoc in Zeilinger's group[39] is used in many laboratories.

The first demonstration of entanglement of orbital angular momentum of photons opened up a new field of research in many laboratories.

In 1998,[45] he provided the final test of Bell's inequality closing the communication loophole by using superfast random number generators.

[49] In an analogous way, his group showed that even quantum systems where entanglement is not possible exhibit non-classical features which cannot be explained by underlying non-contextual probability distributions.

[15] As a member of the group of his thesis supervisor, Helmut Rauch, at the Technical University of Vienna, Zeilinger participated in a number of neutron interferometry experiments at the Institut Laue–Langevin (ILL) in Grenoble.

His very first such experiment confirmed a fundamental prediction of quantum mechanics, the sign change of a spinor phase upon rotation.

Shull (Nobel Laureate), focusing specifically on dynamical diffraction effects of neutrons in perfect crystals which are due to multi-wave coherent superposition.

Zeilinger built a double-slit diffraction experiment[52] on the S18 instrument at the Institut Laue-Langevin which, later on, gained in accuracy and could act with only one neutron at a time in the apparatus.