Certain quantum sensing protocols rely on qubits that are initialized, coherently driven in the presence of a stimulus to be measured, then read out. Most widely employed pulse sequences used to drive sensing qubits act locally in either the time or frequency domain. We introduce a generalized set of sequences that effect a measurement in any fractional Fourier domain, i.e. along a linear trajectory of arbitrary angle through the time-frequency plane. Using an ensemble of nitrogen-vacancy centers we experimentally demonstrate advantages in sensing signals with time-varying spectra.
@article{arxiv.2405.03896,
title = {Quantum sensing in the fractional Fourier domain},
author = {Swastik Hegde and David J. Durden and Lakshmy Priya Ajayakumar and Rishi Sivakumar and Mikael P. Backlund},
journal= {arXiv preprint arXiv:2405.03896},
year = {2025}
}