Magnetic imaging with spin defects in hexagonal boron nitride

TL;DR

This paper demonstrates the use of spin defects in hexagonal boron nitride for quantitative magnetic imaging, showcasing a new 2D quantum sensing technique capable of probing magnetic fields in van der Waals materials.

Contribution

The work introduces a novel 2D quantum sensor based on hBN with boron-vacancy centers for magnetic imaging, highlighting its advantages over traditional 3D sensors.

Findings

Successful magnetic imaging of CrTe₂ using hBN defects

Demonstrated proximity sensing capabilities in 2D materials

Showcased ease of use and high flexibility of the sensor

Abstract

Optically-active spin defects hosted in hexagonal boron nitride (hBN) are promising candidates for the development of a two-dimensional (2D) quantum sensing unit. Here, we demonstrate quantitative magnetic imaging with hBN flakes doped with negatively-charged boron-vacancy (V$_{\rm B}^-$) centers through neutron irradiation. As a proof-of-concept, we image the magnetic field produced by CrTe$_2$, a van der Waals ferromagnet with a Curie temperature slightly above $300$ K. Compared to other quantum sensors embedded in 3D materials, the advantages of the hBN-based magnetic sensor described in this work are its ease of use, high flexibility and, more importantly, its ability to be placed in close proximity to a target sample. Such a sensing unit will likely find numerous applications in 2D materials research by offering a simple way to probe the physics of van der Waals heterostructures.