A statistical quasi-particles thermofield theory with Gaussian environments: System-bath entanglement theorem for nonequilibrium correlation functions

TL;DR

This paper develops a thermofield theory for open quantum systems with Gaussian environments, enabling noise-resolved dynamics and a system-bath entanglement theorem for nonequilibrium correlations, validated numerically.

Contribution

It introduces a dissipaton thermofield theory that models Gaussian environments and derives a system-bath entanglement theorem for nonequilibrium steady-state correlations.

Findings

Numerical validation of the derived relations.

Exact recovery of transport current from the theory.

Effective noise-resolved dynamics for thermofield operators.

Abstract

For open quantum systems, the Gaussian environmental dissipative effect can be represented by statistical quasi-particles, namely, dissipatons. We exploit this fact to establish the dissipaton thermofield theory. The resulting generalized Langevin dynamics of absorptive and emissive thermofield operators are effectively noise-resolved. The system-bath entanglement theorem is then readily followed between an important class of nonequilibrium steady-state correlation functions. All these relations are validated numerically. A simple corollary is the transport current expression, which exactly recovers the result obtained from the nonequilibrium Green's function formalism.