Completely positive dynamical semigroups and quantum resonance theory

TL;DR

This paper develops a quantum dynamical semigroup model for open system evolution, demonstrating its accuracy and exponential convergence to true dynamics using quantum resonance theory.

Contribution

It introduces a new approach based on quantum resonance theory to construct and analyze the accuracy of dynamical semigroups for open quantum systems.

Findings

The semigroup approximation error is linearly small in coupling constant.

The difference between true and approximate dynamics vanishes exponentially over time.

The method applies to microscopic system-environment models.

Abstract

Starting form a microscopic system-environment model, we construct a quantum dynamical semigroup for the reduced evolution of the open system. The difference between the true system dynamics and its approximation by the semigroup has the following two properties: It is (linearly) small in the system-environment coupling constant for all times, and it vanishes exponentially quickly in the large time limit. Our approach is based on the quantum dynamical resonance theory.