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.

中文翻译：

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用超冷气体探测量子速度极限

量子速度限制（QSL）规定了量子状态在任意物理过程中演变为可区分状态的最短时间。这些基本结果就非绝热能量波动所设定的演化速度而言，限制了量子态行进的距离的概念，即所谓的Bures角。我从理论上提出了如何在受限于时间相关的谐波陷阱中的超冷量子气体中测量QSL的方法。在这种高维连续变量系统中，量子层析成像是被禁止的。然而，只要动力学是自相似的，就可以通过测量随时间变化的超冷气体云量来探测QSL。正如我针对各种超冷原子系统所讨论的，这使得确定Bures角和能量波动成为可能。