Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany.
ICFO-Institut de Ciencies Fotoniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels, Barcelona, Spain.
Phys Rev Lett. 2018 Mar 23;120(12):120602. doi: 10.1103/PhysRevLett.120.120602.
Quantum systems strongly coupled to many-body systems equilibrate to the reduced state of a global thermal state, deviating from the local thermal state of the system as it occurs in the weak-coupling limit. Taking this insight as a starting point, we study the thermodynamics of systems strongly coupled to thermal baths. First, we provide strong-coupling corrections to the second law applicable to general systems in three of its different readings: As a statement of maximal extractable work, on heat dissipation, and bound to the Carnot efficiency. These corrections become relevant for small quantum systems and vanish in first order in the interaction strength. We then move to the question of power of heat engines, obtaining a bound on the power enhancement due to strong coupling. Our results are exemplified on the paradigmatic non-Markovian quantum Brownian motion.
量子系统与多体系统强耦合会平衡到全局热态的约化态，与弱耦合极限下系统的局域热态偏离。基于这一认识，我们研究了与热浴强耦合的系统的热力学。首先，我们为适用于三种不同解读的一般系统的第二定律提供了强耦合修正：作为最大可提取功、耗散热量和卡诺效率的陈述。这些修正对于小量子系统变得相关，并在相互作用强度的一阶中消失。然后，我们转向热机功率的问题，得到了由于强耦合而导致的功率增强的限制。我们的结果以典型的非马尔可夫量子布朗运动为例。
