Study of thermal decoherence of harmonic oscillators  

谐振子系统的热力学退相干研究

作　　者：LI Jian ZHOU Gao-Liang YAN Zheng-Xin LIU Wei WANG Zhao-Qi 李俭;周高亮;炎正馨;刘伟;王朝棋(西安科技大学理学院,西安710054)

机构地区：[1]College of Science,Xi’an University of Science and Technology,Xi’an 710054,China

出　　处：《原子与分子物理学报》2025年第5期108-114,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(11805151)。

摘　　要：The thermal decoherence of harmonic oscillators is investigated here.The quantum system presented here is a one-dimensional oscillator with angular frequency,which is surrounded by a thermal bath of environmental oscillators.There are various environmental oscillators with different angular frequency(below an ultraviolet cutoff).At the beginning,the quantum system is a pure state and the environmental oscillators are in thermodynamic equilibrium with temperature.After a period,the system-environment interactions inspire significant decoherence of the quantum state.Such decoherence is displayed by explicit calculations of the purity and von Neumann entropy of the quantum system.It is worth noting that the decoherence could be significant even in the weak coupling and low temperature case due to the large amount of environmental degrees of freedom.Since the decoherence process is inspired between the quantum system and an ordinary thermal environment here,the thermal decoherence result is quite general.研究了谐振子系统的热力学退相干效应.研究工作中的量子系统是一个具有一定角频率的一维谐振子.该量子系统处在角频率低于某个紫外截断的各种热谐振子组成的热浴环境中.初始时刻,量子系统为量子纯态且热浴环境处于热平衡态.经过一段时间后,系统与环境的相互作用导致了量子系统显著的量子退相干效应.通过具体计算该系统的纯度和冯·诺依曼熵来展示这一退相干效应.值得注意的是,由于热浴环境中的大量自由度,即使是在低温环境和弱耦合情况下,量子退相干依然显著.考虑到这一退相干过程是由一个量子系统和一个普通的热环境间的相互作用导致,退相干效应具有一定的普遍性.

关 键 词：Quantum decoherence Grand canonical ensemble Oscillators 

分 类 号：O41[理学—理论物理]