Imaging Light-Matter Interactions and 2D Magnetism with Quantum Sensors

The single electron spin of a defect in diamond known as the nitrogen-vacancy (NV) center has emerged as a versatile nanoscale sensor capable of operation in extreme environments and at diverse interfaces. I will highlight our group's efforts to extend NV quantum sensing to new materials science phenomena and device applications, particularly in atomically thin materials, where such measurements remain challenging for conventional probes. We demonstrate the imaging of light-matter interactions in quantum materials, from the vector photocurrent streamlines in anisotropic Weyl semimetals, uncovering an anisotropic photothermoelectric effect [1], to a transient magnetization enhancement in few-layer magnets driven by exciton recombination [2]. Moreover, we exploit scanning NV magnetometry on 2D antiferromagnets CrPS₄ and CrSBr to elucidate a lateral exchange bias by configurable antiferromagnetic domains [3] and giant electrically-tunable magnetoresistance by space-charge-limited transport [4].

[1] Y.-X. Wang et al. Nature Phys. 19, 507 (2023).

[2] X.-Y. Zhang et al. Phys. Rev. Materials 8, 104402 (2024).

[3] Y.-X. Wang et. al. Nature Mat. 24, 1414 (2025).

[4] T. K. M. Graham et. al. (in preparation).