Nonequilibrium temperature for open boson and fermion systems

A. P. Grigin, É.L. Nagaev

Sang Pyo Kim

The effective theory of an open boson or fermion system is studied, which evolves out of equilibrium with time-dependent Hamiltonian $\hat{H}(t)$. A measure of nonequilibrium temperature for the open system evolving from an equilibrium is proposed as the time-averaged energy expectation value $T(t) = T_i(\bar{< \hat{H} (t) >_Ψ}/ \bar{< \hat{I} (t) >_Ψ})$, where $\hat{I} (t)$, the action operator, satisfies the quantum Liouville-von Neumann equation and determines the true density operator. It recovers the result for the adiabatic (quasi-equilibrium) and nonadiabatic (out of equilibrium) evolution from one static Hamiltonian to another and takes into account the particle production due to the intermediate processes.

M. Fannes

Ralph F. Baierlein

Sang Pyo Kim

We apply the Liouville-von Neumann (LvN) approach to open systems to describe the nonequilibrium quantum evolution. The Liouville-von Neumann approach is a unified method that can be applied to both time-independent (closed) and time-dependent (open) systems and to both equilibrium and nonequilibrium systems. We study the nonequilibrium quantum evolution of oscillator models for open boson and fermion systems

Kim

We apply the Liouville-von Neumann (LvN) approach to open systems to describe the nonequilibrium quantum evolution.The Liouville-von Neumann approach is a unified method that can be applied to both time-independent (closed) and time-dependent (open) systems and to both equilibrium and nonequilibrium systems.We study the nonequilibrium quantum evolution of oscillator models for open boson and fermion systems