Unambiguous nuclear spin detection using engineered quantum sensing sequence

TL;DR

This paper introduces engineered quantum sensing sequences that improve the detection and identification of nuclear spins by suppressing spurious resonances, demonstrated using a nitrogen-vacancy center to detect external protons.

Contribution

The work presents a novel quantum sensing sequence that enhances robustness and suppresses higher order resonances, reducing misidentification in noisy environments.

Findings

Engineered sequences suppress spurious higher order resonances.

Demonstrated unambiguous detection of external protons.

Enhanced robustness in nuclear spin sensing.

Abstract

Sensing, localising and identifying individual nuclear spins or frequency components of a signal in the presence of a noisy environments requires the development of robust and selective methods of dynamical decoupling. An important challenge that remains to be addressed in this context are spurious higher order resonances in current dynamical decoupling sequences as they can lead to the misidentification of nuclei or of different frequency components of external signals. Here we overcome this challenge with engineered quantum sensing sequences that achieve both, enhanced robustness and the simultaneous suppression of higher order harmonic resonances. We demonstrate experimentally the principle using a single nitrogen-vacancy center spin sensor which we apply to the unambiguous detection of external protons.