Thermalization and irreversibility of an isolated quantum system

Xue-Yi Guo

paper

Thermalization and irreversibility of an isolated quantum system

arXiv:2503.04152

Abstract

The irreversibility and thermalization of many-body systems can be attributed to the erasure of spread non-equilibrium state information by local operations. This thermalization mechanism can be demonstrated by the sequence of $O^_{i} (t_{i})$ , where $O_{i}^$ is a local operator, $O_{i}^(t_{i}) = e^{i H^t_{i}} O_{i}^e^{- i H^t_{i}}$ , $H^$ is the system Hamiltonian, $t_{i}$ can take positive, negative, or zero values, and the sequence is arranged according to the subscript $i$ . We numerically demonstrate the information erasure of initial non-equilibrium quantum states through such sequence in a one-dimensional Hubbard model. During this process, the system's entanglement entropy increases monotonically toward a stable value. By incorporating this information erasure mechanism into an isolated system, our numerical simulations reveal that in this completely isolated system, a thermalization process emerges.