Speaker
Description
Arrival-time operators (or observables) describing time-of-flight experiments are naturally constrained by gauge invariance requirements. Surveying the literature on time operators, including POVMs, I will show that a natural generalization of Aharonov-Bohm-Kijowski's arrival-time distribution (referred to as the ``standard arrival-time distribution'' by some authors) fails to be gauge invariant. In particular, this undermines the associated time-energy uncertainty relations. A direct comparison to the quantum flux distribution, which does not exhibit this flaw, and which does not correspond to a quantum observable (or POVM), will be drawn (its acknowledged drawback concerning the quantum backflow effect notwithstanding). Ref: S. Das and M. Nöth, Proc. R. Soc. A. 477 (2021)
