量子体系中自主功的涨落定理
Fluctuation theorems for autonomous work in the quantum regime
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中文总结 AI 辅助
研究将自主功的涨落定理从经典扩展到量子领域，通过对功源和体系连续投影测量推导相关涨落定理，明确纳入功源涨落，量子非对易性影响简化，排他功定义下特定条件可恢复非自主极限，并用Dicke模型说明。
中文摘要 AI 辅助
功的涨落定理对非平衡涨落提供了普遍约束，但其量子推广常依赖外部规定的经典驱动协议。经典体系中涨落定理已扩展到自主功情形，然而其向量子体系的推广受不确定性原理限制。本文将自主功的涨落定理从经典领域扩展到量子领域。通过对功源和体系进行连续投影测量，从初始混合热态推导出自主包含功的Jarzynski型和Crooks型涨落定理。这些关系类似于经典领域中自主功的涨落定理且明确纳入了功源的涨落。量子非对易性阻止了向非自主对应情形的一致简化，即使在大的功源和相应可忽略的反作用极限下也是如此。相比之下，在排他功定义下，当功源的测量可观量与其裸哈密顿量对易且体系对功源的反作用可忽略时，可恢复非自主极限。通过Dicke模型对结果进行了说明，其中单模辐射场和两能级原子系综分别作为感兴趣的体系和功源。
英文摘要
Fluctuation theorems for work provide universal constraints on nonequilibrium fluctuations, yet their quantum generalizations often rely on externally prescribed classical driving protocols. While for classical systems, fluctuation theorems have been extended to autonomous work, where the dynamics of the work source is subject to the backaction of the system, their generalization to the quantum regime is constrained by the uncertainty principle. Here, we extend fluctuation theorems for autonomous work from the classical regime to the quantum regime. By performing successive projective measurements over the work source and the system, we derive Jarzynski-type and Crooks-type fluctuation theorems for autonomous inclusive work from initial mixed thermal states. These relations are analogous to fluctuation theorems for autonomous work in the classical regime and explicitly incorporate the fluctuations of the work source. However, quantum noncommutativity prevents a consistent reduction to the nonautonomous counterparts, even in the limit of a large work source and correspondingly negligible backaction. By contrast, under the exclusive work definition, the nonautonomous limit is recovered when the measured observable of the work source commutes with its bare Hamiltonian and the backaction of the system on the work source is negligible. Our results are illustrated with the Dicke model, where a single-mode radiation field and an ensemble of two-level atoms act as the system of interest and the work source, respectively.
