NV photo-dynamics and superconducting couplers of near-surface NV centers
Prof. Dr. Nir Bar-Gill (Department of Applied Physics and Racah Institute of Physics, Hebrew University, Jerusalem, Israel)

Nitrogen-Vacancy (NV) centers in diamond have been identified over the past few years as promising systems for a variety of applications, ranging from quantum information science to magnetic sensing. Many of these applications require shallow NV centers, i.e. NVs that are close (a few nm) to the diamond surface. However, it is known that some of the properties of shallow NV centers differ from those of bulk NVs, e.g. their coherence is further limited by surface noise [1]. In this talk we focus on the photo-dynamics of shallow NVs, as compared to that of bulk NVs, and on a proposal for coupling such NVs through superconducting structures.

In recent years there has been increasing interest in understanding the dynamics of NV centers under various illumination conditions, specifically under IR excitation, which has been demonstrated to have significant impact on the NV centers’ emission and charge state [2-4].
Several models have been suggested to explain different experimental results [2-4], but a full understanding of all experimental data is still lacking. This situation is further confounded by potential differences between the behavior of bulk and shallow NVs.

Here we suggest a generalized quantitative model for NV center spin and charge state dynamics under both green and IR excitation [5]. We experimentally extract the relevant transition rates, providing a comprehensive model which reconciles all existing results in the literature.
Moreover, we identify key differences between the photo-dynamics of bulk and shallow NVs, and use them to significantly enhance the initialization fidelity of shallow NVs to the useful negatively-charged (NV-) state.

Finally, we present a roadmap for using shallow NVs coupled through nano-fabricated superconducting structures on the diamond surface, with the potential for constructing a platform for quantum simulation and computation.

1. Y. ROMACH ET. AL., PHYS. REV. LETT. 114, 017601 (2015).
2. M. GEISELMANN ET. AL., NATURE PHYSICS 9, 785 (2013).
3. D. A. HOPPER, R. R. GROTE, A. L. EXARHOS, AND L. C. BASSETT, PHYSICAL REVIEW B 94, 241201 (2016).
4. P. JI AND M. V. G. DUTT, PHYSICAL REVIEW B 94, 024101 (2016).
5. I. MERIZADA ET. AL., SUBMITTED (2017).