Lee Historical Lecture: Anton Zeilinger

April 24, 2019
Photo of Anton Zeilinger

The lectures are free and open to the public.


Vienna Center for Quantum Science and Technology, University of Vienna and
Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences

"Quantum Information and Quantum Communication, Foundations and Prospects"

Wednesday, April 24, 2019 @8:00PM
Jefferson 250, 17 Oxford Street, Cambridge

It is curious that the development of quantum physics – arguably the most successful description of nature ever – was accompanied by fundamental debates from the early days until today. Schrödinger’s cat, Einstein’s “spooky action at a distance” and his comment that “God does not play dice with the Universe” are deeply rooted in fundamental features of the theory: superposition, entanglement and randomness. The concept of Quantum Information encompasses these fundamental features. In the talk, I will discuss some fundamental experiments. For example, in delayed-choice entanglement swapping, the decision whether two photons which share no common past are entangled or not can be made at the time when they already have been detected. An interesting and very visual workhorse are orbital angular momentum states of photons. They opened up the possibility for higher-dimensional quantum experiments. That way, entanglement has been confirmed for quantum numbers above 10.000 and between two more than 100-dimensional quantum states. In the talk, I will also mention recent experiments in higher dimensions where the setup has been designed by the computer program Melvin. Finally, a recent Cosmic Bell Test experiment will be discussed, where the randomness is taken from fluctuations of light from distant quasars. The talk will conclude with a most technical application, the implementation of intercontinental quantum cryptography between Beijing and Vienna via the Chinese quantum satellite Micius, and with The Big Bell Test involving 100.000 participants providing independent input for 13 experiments on 5 continents.