Projectiles, rockets and quantum backflow

Projectiles, rockets and quantum backflow

Seminar author:Miguel Navascués

Event date and time:05/19/2022 04:00:pm

Event location:

Event contact:john

Consider a scenario where a non-relativistic one-dimensional quantum particle is prepared in some bounded region of space and left to propagate freely. After a certain amount time, we measure if the particle is in some distant target region. In this talk, I will prove the existence of `ultra-fast’ initial quantum states, for which the probability of arrival is greater than that of any classical system prepared in the same region with the same momentum distribution. Similarly, I will introduce the notion of `ultra-slow’ states, which arrive at the target region with probability strictly smaller than any classical system. Remarkably, the magnitude of such mismatches between classical and quantum predictions is independent of the distance between the preparation and target regions, and it increases with the projectile’s mass. I will relate the maximum possible quantum advantage with the old phenomenon of quantum backflow and explore some variants of the original scenario in order to increase this value.