Quantum thermalization and equilibrium state with multiple temperatures

Abstract

A large class of isolated quantum system in a pure state can equilibrate and serve as a heat bath. We show that once the equilibrium is reached, any of its subsystems that is much smaller than the isolated system is thermalized such that the subsystem is governed by the Gibbs distribution. Within this theoretical framework, the celebrated superposition principle of quantum mechanics leads to a prediction of a thermalized subsystem with multiple temperatures when the isolated system is in a superposition state of energy eigenstates of multiple distinct energy scales. This multiple-temperature state is at equilibrium, completely different from a non-equilibrium state that has multiple temperatures at different parts. Feasible experimental schemes to verify this prediction are discussed.

6 pages, 2 figures

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Cited by in corpus (6)

• Scrambling and Complexity in Phase Space
• Entropy for Quantum Pure States and Its Dynamical Relaxation
• Equilibration of isolated many-body quantum systems with respect to general distinguishability measures
• Quantum Heat Baths satisfying the eigenstate thermalization hypothesis
• Observation of Quantum Equilibration in Dilute Bose Gases
• Roles of energy eigenstates and eigenvalues in equilibration of isolated quantum systems