Nonadiabatic evolution and thermodynamics for a boundary-driven system with a weak intrasubsystem interaction

TL;DR

This paper develops a nonadiabatic master equation for boundary-driven systems with weak intrasystem interactions, clarifying thermodynamic consistency issues and confirming findings with a two-qubit model.

Contribution

It introduces a generalized nonadiabatic master equation for driven systems with weak interactions, extending the local master equation framework.

Findings

Nonadiabatic and local master equations are consistent with the second law away from steady state.

Contradictions arise at steady state between these equations and thermodynamics.

Numerical simulations with a two-qubit model confirm the theoretical analysis.

Abstract

We derive a time-dependent master equation for an externally driven system whose subsystems weakly interact with each other and locally connect to the thermal reservoirs. The nonadiabatic equation obtained here can be viewed as a generalization of the local master equation, which has already been extensively used in describing the dynamics of a boundary-driven system. In addition, we investigate the fundamental reason underlying the thermodynamic inconsistency generated by the local and nonadiabatic master equations. We fnd that these two equations are consistent with the second law of thermodynamics when the system is far away from the steady state, while they give rise to the contradiction at the steady state. Finally, we numerically confrm our results by considering a toy model consisting of two qubits and two local heat baths.