Feldman's group uses scanning NV-diamond magnetometry -- imaging local magnetic fields with a single spin at the tip of a scanning probe -- to visualize currents, magnetism, and correlated-electron order in moire and other quantum materials at the nanoscale, extending the sensitivity/resolution tradeoff of ensemble NV-diamond sensing (DEER/T1 protocols at pT/âHz) down to single-spin, single-defect imaging.