Quantum Sensing of Spin Dynamics in 2D Antiferromagnets using Boron Vacancies in hBN

We report studies of widely dispersed boron vacancies (BV⁻) in thin hexagonal boron nitride (hBN) for enabling high sensitivity optical detection of antiferromagnetic resonance in van der Waals based antiferromagnets (AFMs). BV⁻ centers provide a promising platform for probing spin dynamics in low-dimensional magnetic systems given the ease with which hBN flakes are integrated with atomically thin layers of two-dimensional magnets. This detection mechanism relies on the enhancement of the color-center spin relaxation rate by the dipole field fluctuations arising from magnons generated by Néel vector dynamics in AFMs. Néel vector dynamics can be driven by resonant applied microwave fields or by magnetization switching, making this a potentially powerful platform for understanding dynamical phenomena in AFMs, which is important for spintronic applications requiring efficient Néel vector manipulation in emerging AFM systems.