Dynamical sensitivity control of a single-spin quantum sensor

TL;DR

This paper introduces a method for dynamically controlling the sensitivity of a single NV center spin sensor, enabling high-precision, ambiguity-free magnetometry with enhanced dynamic range and longer interaction times.

Contribution

It presents a novel technique to encode interactions in the NV spin states, allowing continuous sensitivity control and improved quantum sensing capabilities.

Findings

Achieved high-accuracy NV magnetometry without 2pi ambiguities

Enhanced dynamic range by a factor of 4000

Extended interaction times beyond 2 ms

Abstract

The Nitrogen-Vacancy (NV) defect in diamond is a unique quantum system that offers precision sensing of nanoscale physical quantities beyond the current state-of-the-art. Here we present a method to controllably encode the interactions in the population of the spin states, thereby introducing a way to control the sensitivity of a single spin as a continuum in contrast to free-evolution based methods. By adopting this feature we demonstrate high-accuracy NV magnetometry without 2pi ambiguities, enhance the dynamic range by a factor of 4*10^3 achieve interaction times exceeding 2 ms in off-the-shelf diamond. We perform nuclear spin-noise spectroscopy in the frequency domain by dynamically controlling the NV spin's sensitivity piecewise and in a smooth manner thereby precluding harmonic artefacts and undesired interactions. On a broader perspective dynamical sensitivity control provides an elegant handle on the inherent dynamics of quantum systems, while offering decisive advantages for NV centre applications notably in quantum controls and single molecule NMR/MRI.