Covariant thermodynamics of quantum systems: Passivity, semipassivity, and the Unruh effect

摘要

According to the Second Law of Thermodynamics, cycles applied to thermodynamic equilibrium states cannot perform any work (passivity property of thermodynamic equilibrium states), In the presence of matter this can hold only in the rest frame of the matter, as moving matter drives, e.g., windmills and turbines. If. however, a homogeneous and stationary state has the property that no cycle can perform more work than an ideal windmill, then it can be shown that there is some inertial frame here the state is a thermodynamic equilibrium state, This provides a covariant characterization of thermodynamic equilibrium states. In the absence of matter, cycles should perform work only when driven by nonstationary inertial forces caused by the observer's motion. If a (pure) state of a relativistic quantum field theory behaves this way, it satisfies the spectrum condition and exhibits the Unruh effect. (C) 2002 Elsevier Science (USA). [References: 37]