Sub-nanoscale Temperature, Magnetic Field and Pressure sensing with Spin Centers in 2D hexagonal Boron Nitride

TL;DR

This paper demonstrates that negatively charged boron vacancies in hexagonal boron nitride can serve as atomic-scale sensors for temperature, magnetic fields, and pressure, leveraging their spin properties and photoluminescence.

Contribution

It provides a detailed exploration of $V_B^-$ defects in hBN as multi-parameter nanoscale sensors, expanding their potential applications in 2D material heterostructures.

Findings

$V_B^-$ defects exhibit high-spin triplet ground state.

ODMR frequency shifts are sensitive to magnetic fields, temperature, and pressure.

Potential for integration into heterostructures for advanced sensing applications.

Abstract

Spin defects in solid-state materials are strong candidate systems for quantum information technology and sensing applications. Here we explore in details the recently discovered negatively charged boron vacancies ($V_B^-$) in hexagonal boron nitride (hBN) and demonstrate their use as atomic scale sensors for temperature, magnetic fields and externally applied pressure. These applications are possible due to the high-spin triplet ground state and bright spin-dependent photoluminescence (PL) of the $V_B^-$. Specifically, we find that the frequency shift in optically detected magnetic resonance (ODMR) measurements is not only sensitive to static magnetic fields, but also to temperature and pressure changes which we relate to crystal lattice parameters. Our work is important for the future use of spin-rich hBN layers as intrinsic sensors in heterostructures of functionalized 2D materials.