Radio-frequency magnetometry using a single electron spin

TL;DR

This paper demonstrates a robust method for detecting weak radio-frequency magnetic fields using a single electron spin in diamond, achieving high spectral resolution and sensitivity for nanoscale magnetic sensing.

Contribution

The authors introduce a spin locking protocol for radio-frequency magnetometry with a single electron spin, enabling high-resolution detection of weak magnetic fields.

Findings

Detected a 7.5 MHz magnetic field of 40 nT amplitude

Achieved spectral resolution below 10 kHz

Operated near the T_1 noise limit of 0.3 nT/rtHz

Abstract

We experimentally demonstrate a simple and robust protocol for the detection of weak radio-frequency magnetic fields using a single electron spin in diamond. Our method relies on spin locking, where the Rabi frequency of the spin is adjusted to match the MHz signal frequency. In a proof-of-principle experiment we detect a 7.5 MHz magnetic probe field of 40 nT amplitude with <10 kHz spectral resolution over a T_1-limited noise floor of 0.3 nT/rtHz. Rotating-frame magnetometry may provide a direct and sensitive route to high-resolution spectroscopy of nanoscale nuclear spin signals.