Probing Quantum Speed Limits with Ultracold Gases

TL;DR

This paper proposes a method to experimentally measure quantum speed limits in ultracold gases by analyzing cloud size dynamics, enabling insights into quantum evolution speed without full quantum state tomography.

Contribution

It introduces a novel approach to probe quantum speed limits in high-dimensional ultracold gases through cloud size measurements, bypassing the need for quantum tomography.

Findings

QSLs can be measured via cloud size dynamics in ultracold gases.

The method allows determination of Bures angle and energy fluctuations.

Applicable to various ultracold atomic systems.

Abstract

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 travelled by the quantum state, known as the Bures angle, in terms of the speed of evolution set by nonadiabatic energy fluctuations. We 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 possible to determine the Bures angle and energy fluctuations, as we discuss for various ultracold atomic systems.