光纤耦合双光学腔系统的相干动力学

Dynamics of Quantum Coherence in a Fiber-coupled Two-cavity System

为了研究量子相干性在腔量子电动力学系统中的动力学和分布特性,基于两个各自捕获原子系综的光学腔建立了双光学腔系统,腔与腔之间由光纤耦合.利用相对熵度量的量子相干性,引入量子相干非平衡性的概念,分析了系统中相干动力学和光纤-腔耦合强度对相干性分布的影响.结果表明:在强耦合极限下,光纤-腔耦合强度的增加有利于保持两腔中的原子的整体相干性;光纤-腔耦合强度、原子-腔耦合强度以及原子数三个参数之间满足特定条件时,腔内的原子相干性可以传输至另一个腔.考虑腔、光纤及原子都存在耗散的情形,对比了不同耗散速率和非耗散情形下的相干性演化,发现耗散使得耦合双腔系统的相干性以及各个腔中的原子相干性发生衰减.

In order to explore the dynamics and distribution properties of quantum coherence in cavity quantum electro dynamics system, a system was built by connecting two cavities through an optical fiber, where an atomic ensemble could be trapped in each cavity. By employing the quantum relative entropy measure of quantum coherence and introducing the concept of quantum coherence imbalance, the coherence dynamics of the system and the influence of the fiber-cavity coupling strength on the coherence distribution were studied. It is found that the global coherence of the atoms in the two cavities preserves well in the strong coupling limit by increasing the fiber-cavity coupling strength, and perfect transfer of atomic coherence from one cavity to the other cavity can he realized under specific configurations for the fiber-cavity coupling strength, the atom-cavity coupling strength and the atom number. Considering the presence of dissipations for the cavities, fibers and atoms, the evolutions of coherence under different dissipation rates with that in the non-dissipation case were compared. It is shown that the coherence of the coupled two-cavity system and the atomic coherence in each cavity are both reduced by dissipations.