Shot-noise-limited optical polarimetry with spin-alignment and magnetism decoupling

作者：Xing Heng, Xiaofei Huang, Weiyi Wang, Fan Wang, Dinghui Gong, Chang Liu, Guoqing Tian, Jie Zheng, Yueyang Zhai, Kai Wei · 发表于：Results in Physics · 年份：2024 · DOI：10.1016/j.rinp.2024.107960 · 被引用次数：6 · 研究领域：Atomic and Subatomic Physics Research、Quantum optics and atomic interactions、Advanced MRI Techniques and Applications

Quantum non-demolition measurement with an off-resonance polarized probe is a widely utilized technique for atomic sensors. We observe previously unexplored spin-alignment polarization induced by the far-detuned off-resonance linear probe in an ultrasensitive optical polarimetry. The evolution of probe-generated multipole moments exacerbates probe noise due to strong magnetic couplings. We demonstrate a method to decouple spin-alignment from magnetic fields by manipulating the multipole moments in zero-fields. The probe noise is suppressed by 10 dB with the proposed method, achieving a noise floor at the standard quantum limit. The realized shot-noise-limited optical polarimetry holds significant promise for atomic sensors aimed at ultra-sensitivity.