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:

王晓光，浙江理工大学教授，博士生导师，主要研究领域包括量子信息与计算理论，量子精密测量，和凝聚态理论。发表论文200余篇，论文共被SCI引用9000余次。2005年获国务院政府特殊津贴，2010年获得国家杰出科学青年基金，2022年出版教材《理论力学及其专题分析》。