Charge-state control of ensemble of nitrogen vacancy centers by n-i-n diamond junctions

We fabricated n-type-intrinsic-n-type (n-i-n) diamond junctions to stabilize negatively charged nitrogen vacancy (NV%) centers. An ensemble of NV centers was generated in a high-purity intrinsic diamond in order to maintain the spin coherence time. The Fermi-energy of the i-layers was controlled by band bending at the two n-i junctions. We confirmed that the NV centers can be modulated toward NV% centers by decreasing the width of the i-layers between adjacent n-layers. The spin coherence time for the NV% centers was maintained even for narrow i-layers. (C) 2018 The Japan Society of Applied Physics