Supersensitive sensing of quantum reservoirs via breaking antisymmetric coupling

• DOI: 10.48550/arxiv.2310.12445
• Publication Date: 2023-01-01
• Authors: Ji-Bing Yuan; Zhi-Min Tang; Ya‐Ju Song; Shi-Qing Tang; Zhao-Hui Peng; Xin-Wen Wang; Le‐Man Kuang
• Keywords: Dephasing; Antisymmetric relation; Flux qubit

We investigate the utilization of a single generalized dephasing qubit for sensing quantum reservoir, where antisymmetric coupling between and its reservoir is broken. It found that in addition to decay factor encoding channel, breaking gives rise another phase channel. introduce an optimal measurement which enables practical precision reach theoretical ultimate quantified by signal-to-noise ratio (QSNR). As example, employed estimate $s$-wave scattering length atomic Bose-Einstein condensate. phase-induced QSNR caused at least two orders magnitude higher than decay-induced millisecond timescale relative error can achieve scaling $\propto 1/t$ with $t$ being time long-term encoding. Our work opens way supersensitive reservoirs.