近日，湖南理工学院谭庆收团队研究了非马尔可夫量子测温中强耦合的局限性。相关论文于2025年10月20日发表在《物理评论A》杂志上。

研究组分析了嵌入在非马尔可夫环境中的单量子位探针的量子测温，采用数值精确的层次运动方程（HEOM）来克服Born-Markov近似的局限性。通过对量子信噪比（QSNR）用于温度估计的动态和稳态行为的系统分析，研究组确定了几个关键发现，这些发现挑战了传统期望，即强耦合必然提高测温性能。在非平衡态动态测温中，弱系统环境耦合通常产生最优的QSNR，而在稳态状态下，强耦合仅在超低温极限下提高灵敏度，而弱耦合在中低温极限下显著提高精度。

为了优化跨耦合机制的性能，研究组开发了一个混合计算框架，将HEOM与量子增强粒子群优化相结合，在不同耦合强度下实现精确的量子动力学控制。该结果揭示了量子测温的基本限制和机会，为设计在现实开放量子系统中运行的高性能量子温度计提供了实用策略。

附：英文原文

Title: Limitations of strong coupling in non-Markovian quantum thermometry

Author: Qing-Shou Tan, Yang Liu, Xulin Liu, Hao Chen, Xing Xiao, Wei Wu

Issue&Volume: 2025/10/20

Abstract: We investigate quantum thermometry using a single-qubit probe embedded in a non-Markovian environment, employing the numerically exact hierarchical equations of motion (HEOM) to overcome the limitations of Born-Markov approximations. Through a systematic analysis of the dynamical and steady-state behavior of the quantum signal-to-noise ratio (QSNR) for temperature estimation, we identify several key findings that challenge the conventional expectation that strong coupling necessarily enhances thermometric performance. In nonequilibrium dynamical thermometry, weak system-environment coupling generally yields the optimal QSNR, whereas in the steady-state regime, strong coupling enhances sensitivity only in the ultralow-temperature limit, while weak coupling significantly improves precision at moderately low temperatures. To optimize performance across coupling regimes, we develop a hybrid computational framework that integrates HEOM with quantum-enhanced particle swarm optimization, enabling precise quantum dynamical control under varying coupling strengths. Our results reveal fundamental constraints and opportunities in quantum thermometry, offering practical strategies for the design of high-performance quantum thermometers operating in realistic open quantum systems.

DOI: 10.1103/t74h-c8kw

Source: https://journals.aps.org/pra/abstract/10.1103/t74h-c8kw