A method for robust spin relaxometry in the presence of imperfect state preparation

TL;DR

This paper introduces a minimal fitting method to improve the accuracy of spin relaxometry measurements with NV centers, especially when spin state preparation is imperfect, enhancing robustness and efficiency.

Contribution

A novel minimal fitting procedure that accounts for imperfect spin polarization, leading to more accurate and robust parameter estimation in spin relaxometry.

Findings

Enhanced accuracy in T1 relaxation time estimation.

Robustness against artifacts from imperfect spin state preparation.

Framework for parallelizing single-spin dynamics studies.

Abstract

Spin relaxometry based on quantum spin systems has developed as a valuable tool in medical and condensed matter systems, offering the advantage of operating without the need for external DC or RF fields. Spin relaxometry with nitrogen-vacancy (NV) centers has been applied to paramagnetic sensing using both single crystal diamond and nanodiamond materials. However, these methods often suffer from artifacts and systematic uncertainties, particularly due to imperfect spin state preparation, leading to artificially fast T$_1$ relaxation times. Current analysis techniques fail to adequately account for these issues, limiting the precision of parameter estimation. In this work, we introduce a minimal fitting procedure that enables more robust parameter estimation in the presence of imperfect spin polarization. Our model improves upon existing approaches by offering more accurate fits and provides a framework for efficiently parallelizing single-spin dynamics studies.