title: Canonical versus noncanonical equilibration dynamics of open quantum systems.
abstract: In statistical mechanics, any quantum system in equilibrium with its weakly coupled reservoir is described by a canonical state at the same temperature as the reservoir. Here, by studying the equilibration dynamics of a harmonic oscillator interacting with a reservoir, we evaluate microscopically the condition under which the equilibration to a canonical state is valid. It is revealed that the non-Markovian effect and the availability of a stationary state of the total system play a profound role in the equilibration. In the Markovian limit, the conventional canonical state can be recovered. In the non-Markovian regime, when the stationary state is absent, the system equilibrates to a generalized canonical state at an effective temperature; whenever the stationary state is present, the equilibrium state of the system cannot be described by any canonical state anymore. Our finding of the physical condition on such noncanonical equilibration might have significant impact on statistical physics. A physical scheme based on circuit QED is proposed to test our results.
authors.affiliation: Center for Interdisciplinary Studies, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China and Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology in China Aerospace Science and Technology Corporation, Beijing 100094, China.
authors.forename: Chun-Jie
authors.initials: CJ
authors.lastname: Yang
authors.affiliation: Center for Interdisciplinary Studies, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China and Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore.
authors.forename: Jun-Hong
authors.initials: JH
authors.lastname: An
authors.affiliation: Center for Interdisciplinary Studies, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China and Beijing Computational Science Research Center, Beijing 100084, China.
authors.forename: Hong-Gang
authors.initials: HG
authors.lastname: Luo
authors.affiliation: Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology in China Aerospace Science and Technology Corporation, Beijing 100094, China.
authors.forename: Yading
authors.initials: Y
authors.lastname: Li
authors.affiliation: Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, Singapore 117543, Singapore.
authors.forename: C H
authors.initials: CH
authors.lastname: Oh
mesh_terms: D015233:Models, Statistical; D011789:Quantum Theory