强耦合多体开放量子系统的功分布
Work distribution for strongly coupled many-body open quantum systems
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中文总结 AI 辅助
本文针对强耦合多体开放量子系统，扩展含时数值重整化群（TDNRG）方法计算量子功分布函数，揭示了功趋近最小值时的幂律阈值行为及普适标度崩塌。
中文摘要 AI 辅助
多体开放系统的非平衡量子热力学具有众所周知的丰富性，尤其是在强耦合 regime 中，会形成强的系统-环境关联，且相互作用会产生非微扰效应。这类系统可由“量子杂质模型”描述，其中系统和环境被视为一个整体，处于同等地位。典型例子包括自旋-玻色模型和安德森杂质模型，其中系统自由度分别与玻色型或费米型无间隙环境相互作用。本文研究这类系统在猝灭后的量子功分布函数（WDF）。要捕捉 WDF 中多体激发的完整连续谱，需要对潜在的非平衡量子杂质问题进行非微扰求解。为此，我们将含时数值重整化群（TDNRG）方法扩展到 WDF 的计算，该方法直接适用于热力学极限，可用于零温或有限温度下任意猝灭幅度，且能提供指数级精细的低能分辨率。我们的数值精确解揭示，当功趋近于其最小值时，由于安德森正交灾难会出现幂律阈值行为，且在系统-环境关联诱导的涌现低能标度以下，分布会呈现普适标度崩塌。
英文摘要
The non-equilibrium quantum thermodynamics of many-body open systems is notoriously rich, especially in the strong-coupling regime where strong system-bath correlations develop and interactions produce non-perturbative effects. Such systems can be described by `quantum impurity models' where the system and bath are treated on an equal footing as a single composite. Paradigmatic examples are the spin-boson and Anderson impurity models, in which system degrees of freedom interact with either bosonic or fermionic gapless baths. Here we study the quantum work distribution function (WDF) of such systems following a quench. Capturing the full continuum of many-body excitations in the WDF requires a non-perturbative solution of the underlying non-equilibrium quantum impurity problem. For this purpose, we extend the time-dependent numerical renormalization group (TDNRG) approach to the calculation of the WDF, which applies directly in the thermodynamic limit, can be used for arbitrary quench amplitudes at zero or finite temperature, and provides exponentially fine low-energy resolution. Our numerically-exact solution reveals power-law threshold behavior due to the Anderson orthogonality catastrophe when the work approaches its minimum value, with universal scaling collapse of the distribution below an emergent low-energy scale induced by system-bath correlations.
