Frustration of Decoherence in Open Quantum Systems

TL;DR

This paper investigates a unique open quantum system model where decoherence is frustrated, preventing overdamped dynamics even at strong environmental coupling, due to quantum mechanical coupling effects.

Contribution

It introduces a novel impurity model that resists overdamped behavior, contrasting with traditional dissipative models, and analyzes it using renormalization group techniques.

Findings

The model never exhibits overdamped dynamics even at strong coupling.

Quantum mechanical nature of the coupling causes the frustration of decoherence.

Provides analytic and numerical expressions for susceptibility across regimes.

Abstract

We study a model of frustration of decoherence in an open quantum system. Contrary to other dissipative ohmic impurity models, such as the Kondo model or the dissipative two-level system, the impurity model discussed here never presents overdamped dynamics even for strong coupling to the environment. We show that this unusual effect has its origins in the quantum mechanical nature of the coupling between the quantum impurity and the environment. We study the problem using analytic and numerical renormalization group methods and obtain expressions for the frequency and temperature dependence of the impurity susceptibility in different regimes.