原子-微腔耦合系统的远程量子相干及量子相变

Long-Range Quantum Coherenceand Quantum Phase Transition in Atom-Microcavity Coupled System

通过原子-微腔耦合体系,在绝热近似条件下得到了系统的有效哈密顿量,实现了海森堡自旋XY模型的量子模拟过程。为了获取量子资源,基于相对熵判据分析了任意两体量子系统的量子相干性。通过严格的解析过程获得了在任意间距下两个微腔原子系统的量子相干度。随两体间距增大,远程量子相干度按幂指数规律逐渐减小。当改变系统参量时,远程量子相干度在量子临界点附近出现了数值突变现象,这为表征量子相变提供了一种可能的序参量。在考虑光场噪声对量子相干性影响后,量子相干度随着时间振荡衰减,并逐渐消失。

In this study,the quantum simulation of the Heisenberg spin XY model is realized by obtaining the effective Hamiltonian of the atom-microcavity coupled systems via adiabatic approximation.Further,the quantum coherence between any two-body quantum systems is analyzed based on the criterion of relative entropy to obtain quantum resources.The long-range quantum coherence decreases exponentially with increasing the two-body spacing.Furthermore,when the system parameters are varied,it is found that there is a numerical mutation in the long-range quantum coherence near the quantum critical point,which provides a possible order parameter for characterizing the quantum phase transition.After considering the influence of external light-field noise on the quantum coherence,it is found that the quantum coherence decays with time and gradually disappears.