Role of exchange interaction in nitrogen vacancy center based magnetometry

Abstract

We propose a multilayer device comprising of a thin-film-based ferromagnetic hetero-structure (FMH) deposited on a diamond layer doped with nitrogen vacancy centers (NVC's). We find that when the NVC's are in close proximity (1-2 nm) with the FMH, the exchange energy is comparable to, and may even surpass the magnetostatic interaction energy. This calls for the need to consider and utilize both effects in magnetometry based on NVC's in diamond. As the distance between the FMH and NVC is decreased to the sub-nanometer scale, the exponential increase in the exchange energy suggests spintronic applications of NVC beyond magnetometry, such as detection of spin-Hall effect or spin currents.

Magnon condensation in a dense nitrogen-vacancy spin ensemble

“…While the sp 3 -hybrid orbital basis used here for estimating J ex is rudimentary compared to more sophisticated electron structure calculations, this approach has been previously employed [48], and the estimated values show an order of magnitude and trend that is consistent with values obtained using a tight-binding basis [41,49].…”