Quantum-assisted Distortion-free audio signal sensing

TL;DR

This paper introduces a quantum sensing protocol that significantly enhances dynamic range and reduces distortion in audio and radio signal detection using nitrogen-vacancy centers, enabling high-fidelity, multi-band sensing.

Contribution

It combines quantum phase-sensitive detection with heterodyne readout to achieve distortion-free sensing over a broad dynamic range, demonstrated experimentally with NV centers.

Findings

Achieved 98 dB linear dynamic range in radio signal sensing

Demonstrated high-fidelity quantum-assisted audio signal sensing

Enabled arbitrary frequency resolution in quantum sensing

Abstract

Quantum sensors are keeping the cutting-edge sensitivities in metrology. However, for high-sensitive measurements of arbitrary signals, limitations in linear dynamic range could introduce distortions when sensing the frequency, magnitude and phase of unknown signals. Here, we overcome these limitations with advanced sensing protocol that combines quantum phase-sensitive detection with heterodyne readout. We present theoretical and experimental investigations using nitrogen-vacancy centers in diamond, showing the ability to sense radio signals with a 98 dB linear dynamic range, a 31 pT/Hz$^{1/2}$ sensitivity, and arbitrary frequency resolution. Further, we perform the quantum-assisted distortion-free audio signal (melody, speech) sensing with high fidelity. The methods developed here could broaden the horizon for quantum sensors towards applications in telecommunication, where high-fidelity and low-distortion at multiple frequency bands within small sensing volumes are required.