非相互作用量子链子系统动力学的耗散框架
Dissipative framework for subsystem dynamics of noninteracting quantum chains
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中文总结 AI 辅助
本文开发了具有多项式计算复杂度的耗散框架，用于重构非相互作用量子链的局域动力学生成元，通过两类模型揭示了子系统与环境耦合强度对动力学性质的影响，突破了传统弱耦合近似的局限。
中文摘要 AI 辅助
当仅关注多体量子系统的局域可观测量时，需在对应子系统的希尔伯特空间内构建约化描述，将其余自由度视为环境并求迹。假设初始态无关联且环境为高斯型，我们开发了一种具有多项式计算复杂度的框架，用于重构非相互作用量子链的局域动力学生成元。作为应用，我们考虑两个代表性模型：二分Kitaev链，以及与全连通自由费米子环境边界耦合的Kitaev链。在这两个模型中，强子系统-环境耦合会导致非马尔可夫动力学，其特征是Lindblad耗散子在子系统内的弹道式扩展；而与全连通环境的弱耦合则产生主要定域在边界的马尔可夫耗散。我们的工作强调了子系统-环境关联对局域动力学生成元的影响，超出了传统弱耦合近似的范畴。
英文摘要
When only local observables of a many-body quantum system are of interest, it is desirable to formulate a reduced description within the Hilbert space of the corresponding subsystem, with the remaining degrees of freedom traced out and acting as an environment. Assuming initially uncorrelated states and Gaussian environments, we develop a framework for reconstructing the local dynamical generator of noninteracting quantum chains, with polynomial computational complexity. As an application, we consider two representative models: a bipartitioned Kitaev chain and a Kitaev chain boundary-coupled to a fully connected free-fermion environment. In both models, strong subsystem-environment coupling leads to non-Markovian dynamics characterized by ballistic spreading of the Lindblad dissipator support within the subsystem. On the other hand, weak coupling to a fully connected environment yields predominantly boundary-localized, Markovian dissipation. Our work highlights the implications of subsystem-environment correlations on the generator of local dynamics, beyond the conventional weak-coupling approximations.
