Electron spin resonance microscopic surface imaging using a microwave scanning probe

We report on a scanning electron-spin-resonance microscopy based on a microwave near-field probe. The probe consists of an open dielectric resonator with a thin-slit aperture. The spatial resolution in one direction is determined by the slit width and can be varied between 1 and 100 μm, while the spatial resolution in the perpendicular direction is ∼10 times larger. We demonstrate spatially-resolved measurements on diphenyl-picryl-hydrazil samples on a substrate. A sensitivity of 1011 spins could be achieved using a 4-μm-wide slit operating at 8.5 GHz and in a contact mode.