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arXiv · 2501.15769

Enhancement of sensitivity near exceptional points in dissipative qubit-resonator systems

Pei-Rong Han·Fan Wu·Xin-Jie Huang·Huai-Zhi Wu·Chang-Ling Zou·Wei Yi·Mengzhen Zhang·Hekang Li·Kai Xu·Dongning Zheng·Heng Fan·Jianming Wen·Zhen-Biao Yang·Shi-Biao Zheng
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Abstract

Dissipation usually plays a negative role in quantum metrological technologies, which aim to improve measurement precision by leveraging quantum effects that are vulnerable to environment-induced decoherence. Recently, it has been demonstrated that dissipation can actually be used as a favorable resource for enhancing the susceptibility of signal detection. However, demonstrations of such enhancement for detecting physical quantities in open quantum systems are still lacking. Here we propose and demonstrate a protocol for realizing such non-Hermitian quantum sensors for probing the coupling between a qubit and a resonator subjecting to energy dissipations. The excitation-number conversion associated with the no-jump evolution trajectory enables removal of the noisy outcomes with quantum jumps, implementing the exceptional point (EP), where the Rabi splitting exhibits a divergent behavior in response to a tiny variation of the effective coupling. The sensitivity enhancement near the EP is confirmed by both theoretical calculation and experimental measurement.

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Pei-Rong Han, Fan Wu, Xin-Jie Huang, Huai-Zhi Wu, Chang-Ling Zou, Wei Yi, Mengzhen Zhang, Hekang Li, Kai Xu, Dongning Zheng, Heng Fan, Jianming Wen, Zhen-Biao Yang, Shi-Biao Zheng. 2025-01-27. Enhancement of sensitivity near exceptional points in dissipative qubit-resonator systems. https://doi.org/10.1002/qute.202400446

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