Pulse-phase control for spectral disambiguation in quantum sensing protocols

TL;DR

This paper introduces a pulse-phase control method to distinguish genuine signals from artifacts caused by finite-width pulses in quantum sensing, improving spectral accuracy in both classical and quantum regimes.

Contribution

The authors develop a phase-based technique to identify and eliminate spurious signals in quantum sensing protocols, enhancing spectral interpretation accuracy.

Findings

Oscillations in spurious signals depend on initial phase changes.

Real resonances remain unaffected by phase adjustments.

Method extends to quantum regime for nuclear spin detection.

Abstract

We present a method to identify spurious signals generated by finite-width pulses in quantum sensing experiments and apply it to recently proposed dynamical decoupling sequences for accurate spectral interpretation. We first study the origin of these fake resonances and quantify their behavior in a situation that involves the measurement of a classical magnetic field. Here we show that a change of the initial phase of the sensor or, equivalently, of the decoupling pulses leads to oscillations in the spurious signal intensity while the real resonances remain intact. Finally we extend our results to the quantum regime for the unambiguous detection of remote nuclear spins by utilization of a nitrogen vacancy sensor in diamond.