Saturation of entropy production in quantum many-body systems.

摘要: Bridging the second law of thermodynamics and microscopic reversible dynamics has been a longstanding problem in statistical physics. Here, we address this on basis quantum many-body physics, discuss how entropy production saturates isolated systems under unitary dynamics. First, rigorously prove that does indeed saturate long time regime, even when total system is pure state. Second, non-negativity at saturation, implying thermodynamics. This based eigenstate thermalization hypothesis, which states single energy thermal. We also numerically demonstrate non-negative value initial state heat bath eigenstate. Our results reveal fundamental properties late times.