Many-Body Perturbation Theory for Driven Dissipative Quasiparticle Flows and Fluctuations

TL;DR

This paper develops a comprehensive many-body perturbation theory for open quantum systems, enabling systematic treatment of dissipation, correlations, and external driving with practical diagrammatic tools and applications to quantum materials.

Contribution

It introduces a unified diagrammatic approach using Keldysh-Lindblad formalism for dissipative quasiparticle flows, preserving symmetries and enabling existing numerical methods to be applied.

Findings

Derived dissipative versions of second Born and GW approximations.

Demonstrated efficient simulation of relaxation and decoherence dynamics.

Applied framework to the driven Haldane model showing long-lived quasiparticles.

Abstract

We present a unified many-body perturbation theory for open quantum systems, that treats dissipation, correlations, and external driving on equal footing. Using a Keldysh-Lindblad formalism, we introduce diagrammatic treatment of dissipative interaction lines representing quasiparticle flows and fluctuations. Two new Feynman rules render the evaluation of dissipative diagrams compact and systematically improvable, while preserving the Keldysh and anti-Hermitian symmetries of the closed-system theory. Consequently, the structure of the Kadanoff-Baym equations (KBE) remains unchanged, enabling existing numerical methods to be directly applied. To illustrate this, we derive dissipative versions of the second Born and $GW$ approximations, identifying the physical content of the self-energy components. Moreover, we demonstrate that time-linear approximations to the full KBE retain their closed structure and can be efficiently used to simulate relaxation and decoherence dynamics. The impact of dissipation-induced correlations is illustrated in the driven Haldane model, where quasiparticles exhibit nontrivial stabilization and acquire lifetimes that far exceed those of the bare system. This framework establishes a general route toward first-principles modeling of correlated, driven, and dissipative quantum materials.