Kolář Michal, Ryabov Artem, Filip Radim
Palacký University, Department of Optics, 17. listopadu 1192/12, 771 46, Olomouc, Czech Republic.
Charles University, Faculty of Mathematics and Physics, Department of Macromolecular Physics, V Holešovičkách 2, 180 00, Praha, Czech Republic.
Sci Rep. 2019 Jul 26;9(1):10855. doi: 10.1038/s41598-019-47288-0.
Coherent quantum oscillators are basic physical systems both in quantum statistical physics and quantum thermodynamics. Their realizations in lab often involve solid-state devices sensitive to changes in ambient temperature. We represent states of the solid-state optomechanical oscillator with temperature-dependent frequency by equivalent states of the mechanical oscillator with temperature-dependent energy levels. We interpret the temperature dependence as a consequence of strong coupling between the oscillator and the heat bath. We explore parameter regimes corresponding to anomalous behavior of mechanical and thermodynamic characteristics as a consequence of the strong coupling: (i) The localization and the purification induced by heating, and (ii) the negativity of two generalized heat capacities. The capacities can be used to witness non-linearity in the temperature dependency of the energy levels. Our phenomenological experimentally-oriented approach can stimulate development of new optomechanical and thermomechanical experiments exploring basic concepts of strong coupling thermodynamics.
相干量子振荡器是量子统计物理学和量子热力学中的基本物理系统。它们在实验室中的实现通常涉及对环境温度变化敏感的固态器件。我们用具有温度依赖能级的机械振荡器的等效状态来表示具有温度依赖频率的固态光机械振荡器的状态。我们将温度依赖性解释为振荡器与热库之间强耦合的结果。我们探索由于强耦合而导致机械和热力学特性出现异常行为的参数区域：（i）加热引起的局域化和纯化，以及（ii）两种广义热容量的负值。这些热容量可用于证明能级温度依赖性中的非线性。我们基于实验的唯象方法可以刺激新的光机械和热机械实验的发展，这些实验探索强耦合热力学的基本概念。
