Title: Constructing the nonclassical lifetime distribution of two-level systems via quantum reliability

Speaker: 王晓光 教授

        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10000余次。2005年获国务院政府特殊津贴，2010年获得国家杰出青年科学基金，2022年出版教材《理论力学及其专题分析》，2025年以首席科学家主持“量子通信与量子计算机”国家科技重大专项一项。

Abstract:

    To characterize the aging process of quantum devices, the concept of quantum reliability has recently been proposed as a process-based metric that quantifies the duration during which operations remain unaffected by noise. This duration is referred to as the lifetime of a quantum system. In this paper, we investigate the lifetime of a two-level atomic system undergoing spontaneous emission. We construct an exact statistical ensemble of the lifetimes for two-level systems using quantum reliability theory, incorporating comprehensive information such as mean values, fluctuations, and non-classical properties. Notably, we demonstrate that the ensemble exhibits can be represented by a density matrix, which is recorded in the monitoring apparatus by an observation process. Under the Born-Markov approximation, the diagonal elements decay exponentially at a state-dependent rate related to quantum fidelity. Beyond this approximation, the off-diagonal elements arise from interference between radiation pathways and are determined by the first-order coherence of the field. This feature indicates that the off-diagonal elements encode spectral information beyond the Markovian decay rate, suggesting a potential protocol for probing the environmental spectral density using two-level atoms.

2026-06-01,14:00-15:00，厚义楼216室