Magnetic field imaging with nitrogen-vacancy ensembles

Abstract

We demonstrate a method of imaging spatially varying magnetic fields using a thin layer of nitrogen-vacancy (NV) centers at the surface of a diamond chip. Fluorescence emitted by the two-dimensional NV ensemble is detected by a CCD array, from which a vector magnetic field pattern is reconstructed. As a demonstration, ac current is passed through wires placed on the diamond chip surface, and the resulting ac magnetic field patterns are imaged using an echo-based technique with sub-micron resolution over a 140?m×140?m field of view, giving single-pixel sensitivity ∼ 100 nT/p √Hz. We discuss ongoing efforts to further improve the sensitivity, as well as potential bioimaging applications such as real-time imaging of activity in functional, cultured networks of neurons. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.