Thermometry of ultracold atoms via non-equilibrium work distributions

TL;DR

This paper presents a novel thermometry method for ultracold atoms that leverages non-equilibrium work distributions and minimal prior knowledge, potentially enabling accurate temperature measurement at subnanokelvin levels.

Contribution

The authors introduce a universal thermometry protocol based on the Tasaki-Crooks theorem, applicable to cold-atom systems with minimal state knowledge and non-destructive measurement.

Findings

Method accurately estimates subnanokelvin temperatures.

Protocol is minimally invasive and broadly applicable.

Demonstrated effectiveness in cold-atom system examples.

Abstract

Estimating the temperature of a cold quantum system is difficult. Usually, one measures a well-understood thermal state and uses that prior knowledge to infer its temperature. In contrast, we introduce a method of thermometry that assumes minimal knowledge of the state of a system and is potentially non-destructive. Our method uses a universal temperature-dependence of the quench dynamics of an initially thermal system coupled to a qubit probe that follows from the Tasaki-Crooks theorem for non-equilibrium work distributions. We provide examples for a cold-atom system, in which our thermometry protocol may retain accuracy and precision at subnanokelvin temperatures.