Three-level spin system under decoherence-minimizing driving fields: Application to nitrogen-vacancy spin dynamics

TL;DR

This paper investigates a three-level NV spin system under specially designed multi-level driving fields aimed at minimizing decoherence, demonstrating that such driving effectively preserves quantum coherence in the presence of environmental noise.

Contribution

It introduces a novel multi-level driving scheme that reduces decoherence in NV spins, validated through theoretical analysis and numerical simulations.

Findings

The multi-level driving scheme minimizes coherence loss.

Purity and entropy quantify improved coherence.

Application to NV centers in a spin bath environment.

Abstract

Within the framework of a general three-level problem, the dynamics of the nitrogen-vacancy (NV) spin is studied for the case of a special type of external driving consisting of a set of continuous fields with decreasing intensities. Such a set has been proposed for minimizing coherence losses. Each new driving field with smaller intensity is designed to protect against the fluctuations induced by the driving field at the preceding step with larger intensity. We show that indeed this particular type of external driving minimizes the loss of coherence, using purity and entropy as quantifiers for this purpose. As an illustration, we study the coherence loss of an NV spin due to a surrounding spin bath of $^{13}$C nuclei.