Oh Sangchul, Park Jung Jun, Nha Hyunchul
Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha, Qatar.
Korea Institute for Advanced Study, 85 Hoegiro, Dongdaemun-gu, Seoul 02455, Korea.
Entropy (Basel). 2020 Jun 20;22(6):693. doi: 10.3390/e22060693.
We investigate the quantum thermodynamics of two quantum systems, a two-level system and a four-level quantum photocell, each driven by photon pulses as a quantum heat engine. We set these systems to be in thermal contact only with a cold reservoir while the heat (energy) source, conventionally given from a hot thermal reservoir, is supplied by a sequence of photon pulses. The dynamics of each system is governed by a coherent interaction due to photon pulses in terms of the Jaynes-Cummings Hamiltonian together with the system-bath interaction described by the Lindblad master equation. We calculate the thermodynamic quantities for the two-level system and the quantum photocell including the change in system energy, the power delivered by photon pulses, the power output to an external load, the heat dissipated to a cold bath, and the entropy production. We thereby demonstrate how a quantum photocell in the cold bath can operate as a continuum quantum heat engine with a sequence of photon pulses continuously applied. We specifically introduce the power efficiency of the quantum photocell in terms of the ratio of output power delivered to an external load with current and voltage to the input power delivered by the photon pulse. Our study indicates a possibility that a quantum system driven by external fields can act as an efficient quantum heat engine under non-equilibrium thermodynamics.
我们研究了两个量子系统的量子热力学，一个是两能级系统，另一个是四能级量子光电池，它们各自作为量子热机由光子脉冲驱动。我们将这些系统设置为仅与冷库处于热接触状态，而传统上由热库提供的热（能量）源则由一系列光子脉冲提供。每个系统的动力学由基于Jaynes - Cummings哈密顿量的光子脉冲相干相互作用以及由Lindblad主方程描述的系统 - 浴相互作用所支配。我们计算了两能级系统和量子光电池的热力学量，包括系统能量变化、光子脉冲传递的功率、输出到外部负载的功率、耗散到冷浴的热量以及熵产生。由此我们证明了处于冷浴中的量子光电池如何能够作为一个连续量子热机运行，其中一系列光子脉冲持续施加。我们具体根据输出到具有电流和电压的外部负载的功率与光子脉冲传递的输入功率之比引入了量子光电池的功率效率。我们的研究表明，在非平衡热力学下，由外部场驱动的量子系统有可能作为高效量子热机运行。
