Complex Time Evolution of Open Quantum Systems

TL;DR

This paper introduces a unified framework combining path integration and closed time formalism to analyze the complex time evolution of open quantum systems, enabling both perturbative and non-perturbative calculations.

Contribution

It presents a novel compact representation of reduced density matrix evolution and a cluster-type expansion for open quantum systems.

Findings

Demonstrated the framework on simple examples

Facilitated perturbative and non-perturbative calculations

Provided a new approach for analyzing open quantum systems

Abstract

We combine, in a single set-up,the complex time parametrization in path integration, and the closed time formalism of non-equilibrium field theories to produce a compact representation of the time evolution of the reduced density matrix. In this framework we introduce a cluster-type expansion that facilitates perturbative and non-perturbative calculations in the realm of open quantum systems. The technical details of some very simple examples are discussed.