Scientists have successfully visualized spin transfer in van der Waals (vdW) heterostructure systems with unprecedented spatial resolution, on the order of 10 nanometers. This breakthrough was achieved using a novel method based on spin ensembles in hexagonal boron nitride (hBN), which act as quantum sensors. The technique allows for detailed mapping of spin fields generated by electrical currents, revealing how electron angular momentum propagates and transfers in these two-dimensional materials.

The study focused on the interaction between tungsten diselenide (WSe₂), a material with strong spin-orbit coupling, and graphene, an efficient spin conductor. Direct visualization of spin density at the WSe₂/graphene interface allowed for the observation of spin current generation via the inverse spin Hall effect and its subsequent diffusion into graphene. This ability to "see" spin transport at the nanoscale is crucial for understanding the fundamental mechanisms governing spintronics in 2D materials.

The developed technique opens new avenues for the design and optimization of spintronic devices. By precisely characterizing the charge-to-spin conversion efficiency and spin diffusion length in various vdW heterojunctions, researchers can select and combine materials to create more efficient components. This is fundamental for the development of future computing and data storage technologies based on electron spin, which promise to be faster and more energy-efficient than current electronics.