论文标题
在孤立系统中反向Clausius不平等的实验验证
Experimental verification of a reversed Clausius inequality in an isolated system
论文作者
论文摘要
热力学的第二定律是自然的基本定律。它几乎与Clausius的不平等相关，它可以按照所提供的热量和温度的比例来下降熵的变化。但是，这一结果是一个系统与将其驱动到热状态的热浴接触的前提。对于通过耗散热交换从初始平衡状态移动的孤立系统，预计克劳西乌斯不等式将被逆转。在这里，我们在实验中研究了超速剖宫产的孤立稀释气体的非平衡热力学，可以通过激光冷却技术从平衡中被热化或从平衡中推出。在这两种情况下，我们都通过以位置分辨荧光成像追踪气体的演化来确定相位空间动力学，从中我们评估所有相关的热力学量。我们的结果证实了通常的克劳西乌斯不等式对第一个过程的有效性和第二个转换的逆转Clausius不平等的有效性。
The second law of thermodynamics is a fundamental law of Nature. It is almost universally associated with the Clausius inequality that lower bounds a change in entropy by the ratio of supplied heat and temperature. However, this result presupposes that a system is in contact with a heat bath that drives it to a thermal state. For isolated systems that are moved from an initial equilibrium state by a dissipative heat exchange, the Clausius inequality has been predicted to be reversed. We here experimentally investigate the nonequilibrium thermodynamics of an isolated dilute gas of ultracold Cesium atoms that can be either thermalized or pushed out of equilibrium by means of laser cooling techniques. We determine in both cases the phase-space dynamics by tracing the evolution of the gas with position-resolved fluorescence imaging, from which we evaluate all relevant thermodynamic quantities. Our results confirm the validity of the usual Clausius inequality for the first process and of the reversed Clausius inequality for the second transformation.
