Quantum sensing of temperature close to absolute zero in a Bose-Einstein condensate
Abstract
We propose a theoretical scheme for quantum sensing of temperature close to absolute zero in a quasi-one-dimensional Bose-Einstein condensate (BEC). In our scheme, a single-atom impurity qubit is used as a temper-ature sensor. We investigate the sensitivity of the single-atom sensor in estimating the temperature of the BEC. We demonstrate that the sensitivity of the temperature sensor can saturate the quantum Cramer-Rao bound by means of measuring quantum coherence of the probe qubit. We study the temperature sensing performance by the use of quantum signal-to-noise ratio (QSNR). It is indicated that there is an optimal encoding time that the QSNR can reach its maximum in the full-temperature regime. In particular, we find that the QSNR reaches a finite upper bound in the weak coupling regime even when the temperature is close to absolute zero, which implies that the sensing-error-divergence problem is avoided in our scheme. Our work opens a way for quantum sensing of temperature close to absolute zero in the BEC.
Cite
@article{arxiv.2212.08237,
title = {Quantum sensing of temperature close to absolute zero in a Bose-Einstein condensate},
author = {Ji-Bing Yuan and Bo Zhang and Ya-Ju Song and Shi-Qing Tang and Xin-Wen Wang and Le-Man Kuang},
journal= {arXiv preprint arXiv:2212.08237},
year = {2023}
}
Comments
9 pages,9 figures