论文标题
floquet在Lindblad动力学中的特殊轮廓随时间周期性驱动和耗散
Floquet exceptional contours in Lindblad dynamics with time-periodic drive and dissipation
论文作者
论文摘要
孤立的量子系统的动力学是连贯和统一的。与环境的较弱耦合会导致反校正,传统上是用lindblad方程来建模的,用于系统的密度矩阵。从纯状态开始,这样的系统以失业或失业的方式接近稳态(混合或其他方式)。这种过渡发生在林格德超级操作机的特征值堕落中,称为特殊点(EP),其中相应的特征向量凝聚。近年来,由于EPS在经典的实现中所表明的增强的灵敏度和拓扑特征所驱动的,人们对在真正的量子领域中创建特殊点的兴趣产生了兴趣。在这里,我们介绍了一个原型量子量的Floquet分析,其驱动器或消散器强度定期变化。我们考虑具有单个消散器的模型,该模型会产生全局损失(相阻尼)或模式选择性损失(自发发射)。在所有情况下,我们都会发现定期调制导致在小耗散强度下的EP线,并且在参数空间中具有丰富的EP结构。我们的分析和数值结果表明,将Lindblad Liouvillians扩展到Floquet域是一种新的,潜在的首选途径,用于访问瞬态动力学中的特殊点向Lindblad稳态。
The dynamics of an isolated quantum system is coherent and unitary. Weak coupling to the environment leads to decoherence, which is traditionally modeled with a Lindblad equation for the system's density matrix. Starting from a pure state, such a system approaches a steady state (mixed or otherwise) in an underdamped or overdamped manner. This transition occurs at an eigenvalue degeneracy of a Lindblad superoperator, called an exceptional point (EP), where corresponding eigenvectors coalesce. Recent years have seen an explosion of interest in creating exceptional points in a truly quantum domain, driven by the enhanced sensitivity and topological features EPs have shown in their classical realizations. Here, we present Floquet analysis of a prototypical qubit whose drive or dissipator strengths are varied periodically. We consider models with a single dissipator that generate global loss (phase damping) or mode-selective loss (spontaneous emission). In all cases, we find that periodic modulations lead to EP lines at small dissipator strengths, and a rich EP structure in the parameter space. Our analytical and numerical results show that extending Lindblad Liouvillians to the Floquet domain is a new, potentially preferred route to accessing exceptional points in the transient dynamics towards the Lindblad steady state.