近日，英国西苏格兰大学的Maximilien Barbier和朴茨茅斯大学的Arseni Goussev以及印度加尔各答可变能量回旋中心的Shashi C. L. Srivastava合作，证实了二维无界的量子回流。该项研究成果已于2023年3月7日在国际学术期刊《物理评论A》上发表。
该课题组探究了带电粒子在一个有限大小的圆盘上运动的情况，圆盘的中心被钻孔，穿过圆盘中心、与圆盘垂直的方向上穿过一根磁通线。研究人员证明了量子回流可以是无界的(在某种意义上)，这使得该系统成为一个非常有前途的物理平台，可以用来观察这一尚未进行的基本量子现象。
据介绍，量子回流是指量子粒子的概率可以流向与其动量相反的方向，这种反直觉的现象在一维系统中被发现非常微弱和脆弱，其中最大的回流量已被证明是有界的。相比于一维情况，二维系统允许存在简并的能量本征态，从而展现出截然不同的量子回流特征。
附：英文原文
Title: Unbounded quantum backflow in two dimensions
Author: Maximilien Barbier, Arseni Goussev, Shashi C. L. Srivastava
Issue&Volume: 2023/03/07
Abstract: Quantum backflow refers to the counterintuitive fact that the probability can flow in the direction opposite to the momentum of a quantum particle. This phenomenon has been seen to be small and fragile for one-dimensional systems, in which the maximal amount of backflow has been found to be bounded. Quantum backflow exhibits dramatically different features in two-dimensional systems that, in contrast to the one-dimensional case, allow for degenerate energy eigenstates. Here we investigate the case of a charged particle that is confined to move on a finite disk punctured at the center and that is pierced through the center, and normally to the disk, by a magnetic flux line. We demonstrate that quantum backflow can be unbounded (in a certain sense), which makes this system a promising physical platform regarding the yet-to-be-performed experimental observation of this fundamental quantum phenomenon.
DOI: 10.1103/PhysRevA.107.032204
Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.107.032204
来源：科学网 小柯机器人