Quantum microscopy with van der Waals heterostructures

Solid-state spin sensors have the capacity to act as quantum microscopes for probing material properties and physical processes. However, so far, these tools have relied on quantum defects hosted in rigid, three-dimensional (3D) crystals such as diamond, limiting their ability to closely interface with the sample. Here we demonstrate a versatile quantum microscope using point defects embedded within a thin layer of the van der Waals material hexagonal boron nitride. To showcase the multi-modal capabilities of this platform, we assemble two different heterostructures of a van der Waals material in combination with a quantum-active boron nitride flake. We demonstrate time-resolved, simultaneous temperature and magnetic imaging near the Curie temperature of a van der Waals ferromagnet, as well as map out charge currents and Joule heating in an operating graphene device. The straightforward integration of the hexagonal boron nitride quantum sensor with other van der Waals materials will yield substantial practical benefits for the design and measurement of 2D devices.