Engines are open systems that can generate work cyclically, at the expense of an external disequilibrium. They are ubiquitous in nature and technology, but the course of mathematical physics over the last 300 years has tended to make their dynamics in time a theoretical blind spot. This has hampered the usefulness of statistical mechanics applied to active systems, including living matter. We argue that recent advances in the theory of open quantum systems, coupled with renewed interest in understanding how active forces result from positive feedback between different macroscopic degrees of freedom in the presence of dissipation, point to a more realistic description of autonomous engines. We propose a general conceptualization of an engine that helps clarify the distinction between its heat and work outputs. Based on this, we show how the external loading force and the thermal noise may be incorporated into the relevant equations of motion. This modifies the usual Fokker-Planck and Langevin equations, offering a thermodynamically complete formulation of the irreversible dynamics of simple oscillating and rotating engines.
Quantum Statistical Thermal Engine at the BCS-BEC crossover
Pontificia Universidad Católica de Valparaíso(智利天主教瓦帕拉索大学);Universidad Técnica Federico Santa María(费德里科·圣玛丽亚技术大学);Okinawa Institute of Science and Technology Graduate University(冲绳科学技术大学院大学);Universidad San Sebastián(圣塞巴斯蒂安大学)
Thermodynamics of Hamiltonian anyons with applications to quantum heat engines
University of Exeter(埃克塞特大学);Universidad de Granada(格拉纳达大学);Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada(格拉纳达大学卡洛斯一世理论与计算物理研究所)
Leo Szilard指出,麦克斯韦的恶魔可以被机器取代,从而为理解信息的物理本质奠定了基础。Szilard的信息引擎在近一百年后仍然是一个典型的例子,尽管该领域最近有了显着的增长。恶魔扮演的角色可以简化为将可观察的数据映射到用于提取工作的亚稳定存储器。虽然西拉德表明,地图可以机械地实现,但它是先验选择的。如何构建有意义的记忆的选择构成了恶魔的智能。最近,它表明,这也可以自动化。为此,引入了广义的、部分可观察的信息引擎,为理解信息处理的物理性质提供了基础。部分可观测性普遍存在于传感器类型和信息获取带宽有限的实际系统中。广义信息引擎可以在与存储器形成过程不同的温度T' > T下运行工作提取。这使得能够组合处理热机和信息引擎。我们研究智能观察员的物理特性,通过引入一个典型的模型,显示物理丰富性,尽管它的简单性。Szilard引擎的一个小改动--以一个角度插入分隔器--导致了一个部分可观察的Szilard引擎家族。他们的分析显示了恶魔的智能是如何自动化的。对于每个角度和每个T ′/T值,可以找到最佳记忆,使发动机能够以最小的耗散运行。这些最佳记忆是通过算法计算的概率图。我们讨论了如何用一个简单的物理系统来实现它们,描述它们的性能,并将它们的质量与天真的、确定性的可观察量化进行比较。
Some elementary rigorous remark about the replica formalism in the Statistical Physics' approach to threshold phenomena in Computational Complexity Theory