Quantum sensing in the fractional Fourier domain

TL;DR

This paper introduces a new class of quantum sensing sequences that operate in any fractional Fourier domain, enabling improved detection of signals with time-varying spectra, demonstrated with nitrogen-vacancy centers.

Contribution

It presents a generalized set of quantum sensing sequences that work in fractional Fourier domains, expanding beyond traditional time or frequency domain methods.

Findings

Enhanced sensing of time-varying signals using fractional Fourier domain sequences

Experimental validation with nitrogen-vacancy centers showing sensing advantages

Sequences allow measurement along arbitrary angles in the time-frequency plane

Abstract

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.