Quantum frustration of dissipation by a spin bath

TL;DR

This paper studies how a central spin's dissipation and decoherence are affected by coupling to a spin bath, revealing that symmetric coupling can inhibit dissipation but not decoherence, highlighting quantum frustration effects.

Contribution

It demonstrates that symmetric coupling to a spin bath causes quantum frustration, affecting dissipation without preventing decoherence in a central spin system.

Findings

Enhanced central spin dynamics with two-component coupling

Dissipation is frustrated by symmetric coupling

Decoherence remains rapid despite symmetric coupling

Abstract

We investigate the evolution of a central spin coupled to a spin bath without internal dynamics. We compare the cases where the bath couples to one or two components of the spin. It is found that the central spin dynamics is enhanced in the latter case, which may be interpreted as a frustration of dissipation. However, the quantum purity of the spin decays fast in both scenarios. We conclude that symmetric coupling of the bath to two orthogonal components of the spin inhibits dissipation but not decoherence.