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arXiv · 2212.08237

Quantum sensing of temperature close to absolute zero in a Bose-Einstein condensate

Ji-Bing Yuan·Bo Zhang·Ya-Ju Song·Shi-Qing Tang·Xin-Wen Wang·Le-Man Kuang
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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.

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Ji-Bing Yuan, Bo Zhang, Ya-Ju Song, Shi-Qing Tang, Xin-Wen Wang, Le-Man Kuang. 2022-12-16. Quantum sensing of temperature close to absolute zero in a Bose-Einstein condensate. https://doi.org/10.1103/physreva.107.063317

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