Quantum quenches in the Dicke model were studied both in the thermodynamic limit and the finite systems.For the integrable situation in the thermodynamic limit,the generalized Gibbs ensemble can effectively describe t...Quantum quenches in the Dicke model were studied both in the thermodynamic limit and the finite systems.For the integrable situation in the thermodynamic limit,the generalized Gibbs ensemble can effectively describe the energylevel occupations for the quench within the normal phase,but it fails for the quench to the superradiant phase.For the finite systems which are considered non-integrable,the post quench systems were studied by comparing with the thermal ensembles.The canonical ensembles are directly available for the quench within the normal phase.With the increasing of the target coupling strength over the equilibrium phase transition critical point,sudden changes take place for the effective temperature and the distance to the thermal ensembles.The thermalization was also studied by comparing with the results of the microcanonical ensembles.展开更多
In this work, we investigate the heat exchange between two quantum systems whose initial equilibrium states are described by the generalized Gibbs ensemble. First, we generalize the fluctuation relations for heat exch...In this work, we investigate the heat exchange between two quantum systems whose initial equilibrium states are described by the generalized Gibbs ensemble. First, we generalize the fluctuation relations for heat exchange discovered by Jarzynski and Wojcik to quantum systems prepared in the equilibrium states described by the generalized Gibbs ensemble at various generalized temperatures. Secondly, we extend the connections between heat exchange and the Renyi divergences to quantum systems under generic initial conditions. These relations are applicable for quantum systems with conserved quantities and universally valid for quantum systems in the integrable and chaotic regimes.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11147110)the Natural Science Youth Foundation of Shanxi,China(Grant No.2011021003)。
文摘Quantum quenches in the Dicke model were studied both in the thermodynamic limit and the finite systems.For the integrable situation in the thermodynamic limit,the generalized Gibbs ensemble can effectively describe the energylevel occupations for the quench within the normal phase,but it fails for the quench to the superradiant phase.For the finite systems which are considered non-integrable,the post quench systems were studied by comparing with the thermal ensembles.The canonical ensembles are directly available for the quench within the normal phase.With the increasing of the target coupling strength over the equilibrium phase transition critical point,sudden changes take place for the effective temperature and the distance to the thermal ensembles.The thermalization was also studied by comparing with the results of the microcanonical ensembles.
基金This work was supported by the National Natural Science Foundation of China （Grant No. 11604220） and the Startup Fund of Shenzhen University （Grant No. 2016018）.
文摘In this work, we investigate the heat exchange between two quantum systems whose initial equilibrium states are described by the generalized Gibbs ensemble. First, we generalize the fluctuation relations for heat exchange discovered by Jarzynski and Wojcik to quantum systems prepared in the equilibrium states described by the generalized Gibbs ensemble at various generalized temperatures. Secondly, we extend the connections between heat exchange and the Renyi divergences to quantum systems under generic initial conditions. These relations are applicable for quantum systems with conserved quantities and universally valid for quantum systems in the integrable and chaotic regimes.
