报告时间：9月5日 周三 下午3:00
报告人：Lev Vaidman（以色列特拉维夫大学Tel Aviv University）
报告题目： Counterfactual communication
Possibility to communicate between spatially separated regions, without even a single photon passing between the two parties, is an amazing quantum phenomenon. The possibility of transmitting one value of a bit in such a way, the interaction-free measurement, was known for quarter of a century. The protocols of full communication, including transmitting unknown quantum states were proposed only few years ago, but it was shown that in all these protocols the particle was leaving a weak trace in the transmission channel, the trace larger than the trace left by a single particle passing through the channel. However, a simple modification of these recent protocols eliminates the trace in the transmission channel and makes all these protocols truly counterfactual.
Lev Vaidman, born in Leningrad, after winning Physics Olimpiad for high-school students in Sovied Union, studied physics in Israel. He received B. Sc. at Hebrew University, M. Sc. at Weitzmann Institute and Ph.D., under guidance of Yakir Aharonov, at Tel Aviv University. His research is centered in foundations of quantum mechanics and quantum information. He is a theoretical physicist, many of his proposals were implemented in laboratories around the world, but recently he himself became involved in experimental realisations of his ideas. Vaidman is mainly known for introducing teleportation of continuous variables, cryptography with orthogonal states, novel types of quantum measurement: nonlocal, weak, protective, interaction-free. His research of interpretations of quantum mechanics centered in developing the many-worlds interpretation, for which he is apparently the strongest proponent.