Enhanced weak-field sensing using detuned spin squeezing

Mingfeng Wang, Weizhi Qu, Pengxiong Li +2 more

Li-Wen Zhang, Yang Liu, Han-Jie Zhu +1 more

Achieving measurement precision beyond the standard quantum limit (SQL) is a fundamental object in quantum metrology. In this manuscript, we propose a streamlined protocol for weak signal sensing in a trapped-ion spin-oscillator system that simultaneously exploits detuned motional squeezing and spin-oscillator entanglement. By combining these two quantum resources, the phase accumulation in this spin system is significantly accelerated, as a result achieving an exponential improvement in the sensitivity over unsqueezed cases. Remarkably, we show that the significant metrological gain provided by our protocol persists in noisy environments, with the sensitivity remaining below the SQL. In particular, our protocol retains a distinct advantage in the short interrogation time regime, thus demonstrating the practical potential in quantum-enhanced sensing.

Jinye Wei, Jungeng Zhou, Yi Shen +2 more

Xiaoyang Chang, Hao Zhang, Wenxiu Li +4 more

The measurement sensitivity of a cavity could be enhanced for sensing applications in an anomalous dispersion condition. In this paper, we find that when injecting a squeezed vacuum light into a dispersive cavity, the sensitivity could be improved further, even beating the standard quantum limit at the detuning frequencies via controlling the dispersion condition. It is amazing that normal dispersion is superior to anomalous dispersion in improving the measurement sensitivity in the presence of a squeezed vacuum field. It implies this paper could be used to realize high-precision sensing applications.

Jakob Reichel

Kevin C. Cox, Joshua M. Weiner, Graham P. Greve +1 more