THERMODYNAMICS IN UNITARY TIME EVOLUTION

摘要

A brief review is provided on the recent developments on the theory of thermalization under unitary time evolution in isolated quantum systems. In particular, we focus on the theory of equilibration, which states the existence of the effective stationary state, and the eigenstate thermalization hypothesis, which is a scenario for the stationary state being regarded as the microcanonical ensemble. Then, we introduce other possible scenarios and compare them from the viewpoint of the finite-size scaling. We also discuss the relative importance among these scenarios.