Vaidman, Lev

Date:   Tuesday, Apr. 9, 2019
Time:   15:00
Place:   ETH Zurich, Hönggerberg, HIL D 10.2
Host:    Renato Renner

Weak value: a property of a single pre and postselected system

Lev Vaidman
Tel Aviv University, Israel

Weak value of a quantum variable was introduced by Aharonov, Albert and Vaidman in 1988 as an outcome of a standard quantum measurement with weakened coupling performed on an ensemble of pre and postselected systems. A common interpretation of the weak value is a conditional expectation value (with even claims that it is not necessarily a quantum concept). I will argue that it has a deeper meaning as a robust property of a single pre and postselected system. Experimental demonstration supporting this claim will be reported and some controversies about weak values will be discussed. An application of a new paradigm of the past of a quantum particle as the weak value of a projection for a novel alignment method will be reported.