Del Campo Adolfo
Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg, Luxembourg; Donostia International Physics Center, E-20018 San Sebastián, Spain; IKERBASQUE, Basque Foundation for Science, E-48013 Bilbao, Spain; Department of Physics, University of Massachusetts, Boston, Massachusetts 02125, USA and Theory Division, Los Alamos National Laboratory, MS-B213, Los Alamos, New Mexico 87545, USA.
Phys Rev Lett. 2021 May 7;126(18):180603. doi: 10.1103/PhysRevLett.126.180603.
Quantum speed limits (QSLs) rule the minimum time for a quantum state to evolve into a distinguishable state in an arbitrary physical process. These fundamental results constrain a notion of distance traveled by the quantum state, known as the Bures angle, in terms of the speed of evolution set by nonadiabatic energy fluctuations. I theoretically propose how to measure QSLs in an ultracold quantum gas confined in a time-dependent harmonic trap. In this highly-dimensional system of continuous variables, quantum tomography is prohibited. Yet, QSLs can be probed whenever the dynamics is self-similar by measuring as a function of time the cloud size of the ultracold gas. This makes it possible to determine the Bures angle and energy fluctuations, as I discuss for various ultracold atomic systems.
量子速度极限（QSLs）规定了在任意物理过程中量子态演化为可区分状态的最短时间。这些基本结果根据非绝热能量涨落所设定的演化速度，限制了量子态所行进的一种距离概念，即布雷斯角。我从理论上提出了如何在限制于随时间变化的谐振子势阱中的超冷量子气体中测量量子速度极限。在这个连续变量的高维系统中，量子层析成像不可行。然而，只要动力学是自相似的，通过测量超冷气体的云团大小随时间的变化，就可以探测量子速度极限。正如我针对各种超冷原子系统所讨论的那样，这使得确定布雷斯角和能量涨落成为可能。
