[Zurück]

E. Bourgeois, L. Londero, K. Buczak, J. Hruby, M. Gulka, Y. Balasubramaniam, G. Wachter, J. Stursa, K. Dobes, F. Aumayr, M. Trupke, A. Gali, M. Nesladek:
"Enhanced photoelectric detection of NV magnetic resonances in diamond under dual-beam excitation";
Physical Review B, 95 (2017), S. 0414021 - 0414025.

The core issue for the implementation of NV center qubit technology is a sensitive readout of the NV spin
state. We present here a detailed theoretical and experimental study of NV center photoionization processes,
used as a basis for the design of a dual-beam photoelectric method for the detection of NV magnetic resonances
(PDMR). This scheme, based on NV one-photon ionization, is significantly more efficient than the previously
reported single-beam excitation scheme. We demonstrate this technique on small ensembles of ∼10 shallow
NVs implanted in electronic grade diamond (a relevant material for quantum technology), on which we achieve
a cw magnetic resonance contrast of 9%-three times enhanced compared to previous work. The dual-beam
PDMR scheme allows independent control of the photoionization rate and spin magnetic resonance contrast.
Under a similar excitation, we obtain a significantly higher photocurrent, and thus an improved signal-to-noise
ratio, compared to single-beam PDMR. Finally, this scheme is predicted to enhance magnetic resonance contrast
in the case of samples with a high proportion of substitutional nitrogen defects, and could therefore enable the
photoelectric readout of single NV spins.