Biophysics Unit (CSIC-UPV/EHU) and Department of Biochemistry and Molecular Biology, University of the Basque Country, 48080 Bilbao, Spain.
J Chem Phys. 2012 Feb 14;136(6):064115. doi: 10.1063/1.3683441.
Many important processes at the microscale require far-from-equilibrium conditions to occur, as in the functioning of mesoscopic bioreactors, nanoscopic rotors, and nanoscale mass conveyors. Achieving such conditions, however, is typically based on energy inputs that strongly affect the thermal properties of the environment and the controllability of the system itself. Here, we present a general class of far-from-equilibrium processes that suppress the net thermal exchange with the environment by maintaining the Maxwell-Boltzmann velocity distribution intact. This new phenomenon, referred to as ghost equilibrium, results from the statistical cancellation of superheated and subcooled nonequilibrated degrees of freedom that are autonomously generated through a microscale energy sorting process. We provide general conditions to observe this phenomenon and study its implications for manipulating energy at the microscale. The results are applied explicitly to two mechanistically different cases, an ensemble of rotational dipoles and a gas of trapped particles, which encompass a great variety of common situations involving both rotational and translational degrees of freedom.
许多微观尺度上的重要过程都需要发生远离平衡的条件，例如介观生物反应器、纳米转子和纳米尺度质量输送机的功能。然而，实现这些条件通常基于强烈影响环境热性质和系统自身可控性的能量输入。在这里，我们提出了一类普遍的远离平衡过程，通过保持麦克斯韦-玻尔兹曼速度分布完整来抑制与环境的净热交换。这种新现象被称为“幽灵平衡”，它是通过微尺度能量分选过程自主产生的过热和过冷非平衡自由度的统计抵消而产生的。我们提供了观察这种现象的一般条件，并研究了其对微尺度能量操纵的影响。研究结果被明确应用于两个在机制上不同的案例，即旋转偶极子的集合和被捕获粒子的气体，这涵盖了涉及旋转和平移自由度的各种常见情况。
