Breakdown of quantum-classical correspondence and dynamical generation of entanglement

Article

关键词: STATISTICAL-MECHANICS;    ERGODIC THEOREM;    H-THEOREM;    CHAOS;    THERMALIZATION;    DECOHERENCE;    ENTROPY;    PROOF;   

DOI  :  10.1103/PhysRevB.104.174302

来源: SCIE

【 摘 要 】

The exchange interaction arising from particle indistinguishability is of central importance in the physics of many-particle quantum systems. Here we study analytically the dynamical generation of quantum entanglement induced by this interaction in an isolated system, namely, an ideal Fermi gas confined in a chaotic cavity, which is described by a non-Gaussian pure state and evolves unitarily from it. We find that the breakdown of the quantum-classical correspondence of particle motion, via the dramatic change in the spatial structure of the many-body wave function, leads to profound changes of the entanglement. Furthermore, for a class of initial states, the changes engender the approach to thermal equilibrium everywhere in the cavity, with the well-known Ehrenfest time in quantum chaos as the thermalization time. Specifically, the quantum expectation values of various correlation functions at different spatial scales are all determined by the Fermi-Dirac distribution. In addition, by using the reduced density matrix (RDM) and the entanglement entropy (EE) as local probes, we find that the gas inside a subsystem is in equilibrium with that outside, and that its thermal entropy is the EE, even though the whole system is in a pure state.

【 授权许可】

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