Quantum Fourier transform for quantum sensing

TL;DR

This paper demonstrates the use of Quantum Fourier Transform in a hybrid quantum sensor to enhance precision and enable signal demultiplexing, marking a significant step in quantum sensing applications.

Contribution

It presents the first implementation of QFT in a quantum sensor with NV centers, achieving near Heisenberg limited precision and NMR signal demultiplexing.

Findings

QFT enhances quantum sensing precision

Achieved near Heisenberg limited scaling

Demonstrated NMR signal demultiplexing

Abstract

The Quantum Fourier Transformation ($QFT$) is a key building block for a whole wealth of quantum algorithms. Despite its proven efficiency, only a few proof-of-principle demonstrations have been reported. Here we utilize $QFT$ to enhance the performance of a quantum sensor. We implement the $QFT$ algorithm in a hybrid quantum register consisting of a nitrogen-vacancy (NV) center electron spin and three nuclear spins. The $QFT$ runs on the nuclear spins and serves to process the sensor - NV electron spin signal. We demonstrate $QFT$ for quantum (spins) and classical signals (radio frequency (RF) ) with near Heisenberg limited precision scaling. We further show the application of $QFT$ for demultiplexing the nuclear magnetic resonance (NMR) signal of two distinct target nuclear spins. Our results mark the application of a complex quantum algorithm in sensing which is of particular interest for high dynamic range quantum sensing and nanoscale NMR spectroscopy experiments.