标题： 通过实时有效场论的工作统计：应用于量子比特耦合的热浴中工作提取 显示英文标题

标题： Work Statistics via Real-Time Effective Field Theory: Application to Work Extraction from Thermal Bath with Qubit Coupling

摘要： 量子热态已知是被动的，这是热力学第二定律的要求。 本文研究了通过将热浴耦合到自旋、费米子或拓扑类型的量子比特，从而可能提取的功，该量子比特在不同温度下充当量子热态。 提取的功量是从循环非平衡过程中的功统计中推导出来的。 尽管多体系统的功统计已知难以显式计算，但我们通过假设外部驱动源耦合到热态的特定准粒子算符，提出了一种有效的场论方法来解决这个问题。 我们表明，功统计可以用该准粒子的热谱函数简洁地表示。 我们得到了没有量子比特耦合的纯热浴的非微扰功分布函数（WDF）。 在量子比特耦合的情况下，我们得到了二阶WDF，从中可以精确确定功提取的物理区域，以帮助设计量子引擎。 显示英文摘要

摘要： Quantum thermal states are known to be passive, as required by the second law of thermodynamics. This paper studies the possible work extraction via coupling the thermal bath to a qubit of either spin, fermion, or topological types, which acts as a quantum thermal state at different temperatures. The amount of work extraction is derived from the work statistics under a cyclic nonequilibrium process. Though the work statistics of many-body systems are known to be challenging to calculate explicitly, we propose an effective field theory approach to tackle this problem by assuming the externally driven source to couple to a specific quasiparticle operator of the thermal state. We show that the work statistics can be expressed succinctly in terms of this quasiparticle's thermal spectral function. We obtain the non-perturbative work distribution function (WDF) for the pure thermal bath without the qubit coupling. With qubit coupling, we get the second-order WDF, from which the physical regime of work extraction can be pinned down precisely to help devise quantum engines.