论文标题
最小的热环境引起的纠缠突然死亡
Sudden death of entanglement induced by a minimal thermal environment
论文作者
论文摘要
我们研究了两个相互作用的两级系统（Qubits）的动力学，其中一个是孤立的，另一个是在热状态下耦合到单个模式电磁场的动力学。该领域起着小型环境的作用，与通过具有许多自由度的热储层建模环境的通常方法相反。我们找到了所提出的模型的分析解决方案，这使我们能够研究与小环境耦合在两量量系统的特征量子特征上的后果。我们研究量子纠缠和连贯性的时间演变，验证对相关耦合常数的依赖性以及环境有效温度的影响。有趣的是，我们发现在这样一个简单的系统中，突然的死亡和纠缠突然出生都可能发生。我们还讨论了一个不同的分区，其中隔离量子位被认为是由其他量子构成的复合环境耦合的。
We study the dynamics of two interacting two-level systems (qubits) having one of them isolated and the other coupled to a single mode electromagnetic field in a thermal state. The field plays the role of a small environment, in contrast to the usual approach of modeling an environment via a thermal reservoir with many degrees of freedom. We find the analytical solution of the proposed model, which allows us to investigate the consequences of the coupling to the small environment on characteristic quantum features of the two-qubit system. We study the time evolution of quantum entanglement and coherence, verifying the dependence on the relevant coupling constants as well as the influence of the effective temperature of the environment. Interestingly, we find that both sudden death and sudden birth of entanglement may occur in such a simple system. We also discuss a different partition, in which the isolated qubit is considered to be coupled to a composite environment, constituted by the other qubit plus the field mode.
