Abstract:

Considering non-Hermitian systems implemented by utilizing enlarged quantum systems, we determine the fundamental limits for the sensitivity of non-Hermitian sensors from the perspective of quantum information. We prove that non-Hermitian sensors do not outperform their Hermitian counterparts (directly couple to the parameter) in the performance of sensitivity, due to the invariance of the quantum information about the parameter. By scrutinizing two concrete non-Hermitian sensing proposals, which are implemented using full quantum systems, we demonstrate that the sensitivity of these sensors is in agreement with our predictions. Our theory offers a comprehensive and model-independent framework for understanding the fundamental limits of non-Hermitian quantum sensors and builds the bridge over the gap between non-Hermitian physics and quantum metrology.

Short Bio:

王曉光，浙江理工大學教授，博士生導師，主要研究領域包括量子信息與計算理論，量子精密測量，和凝聚態理論。發表論文200余篇，論文共被SCI引用9000余次。2005年獲國務院政府特殊津貼，2010年獲得國家杰出科學青年基金，2022年出版教材《理論力學及其專題分析》。