Magnetic field imaging by hBN quantum sensor nanoarray

TL;DR

This paper demonstrates high-resolution magnetic field imaging using a nanoscale array of boron vacancy defects in hexagonal boron nitride, achieving sub-diffraction spatial resolution and practical sensitivity for quantum sensing applications.

Contribution

The authors developed a method to arrange V$_ ext{B}^-$ quantum sensors in a precise array on measurement targets, enabling nanoscale magnetic field imaging.

Findings

Achieved magnetic field imaging with spatial resolution beyond diffraction limit.

Sensor spots with 100 nm size exhibit a sensitivity of 73.6 μT/Hz^{0.5}.

The technique enables visualization of magnetic fields induced by current in a gold wire.

Abstract

Placing a sensor close to the target at the nano-level is a central challenge in quantum sensing. We demonstrate high-spatial-resolution magnetic field imaging with a boron vacancy (V$_\text{B}^-$) defects array in hexagonal boron nitride with a few 10 nm thickness. V$_\text{B}^-$ sensor spots with a size of (100 nm)$^2$ are arranged periodically with nanoscale precision using a helium ion microscope and attached tightly to a gold wire. The sensor array allows us to visualize the magnetic field induced by the current in the wire with a spatial resolution beyond the diffraction limit. Each sensor exhibits a practical sensitivity of $73.6~\mu\text{T/Hz}^{0.5}$, suitable for quantum materials research. Our technique of arranging V$_\text{B}^-$ quantum sensors periodically and tightly on measurement targets will maximize their potential.