• Lang, J.; Häußler, S.; Fuhrmann, J.; Waltrich, R.; Laddha, S.; Scharpf, J.; Kubanek, A.; Naydenov, B.; Jelezko, F.: Long optical coherence times of shallow-implanted, negatively charged silicon vacancy centers in diamond. Applied Physics Letters 116 (2020), p. 064001/1-5

10.1063/1.5143014

Abstract:
The creation of single, negatively charged silicon vacancy (SiV−) centers in well-defined diamond layers close to the host surface is a crucial step for the development of diamond-based quantum optic devices with many applications in nanophotonics, quantum sensing, or quantum information science. Here, we report on the creation of shallow (10 nm below the surface), single SiV− centers in diamond using low energy Si+ ion implantation with subsequent high temperature annealing at 1500 °C. We show transition linewidths down to 99 MHz and narrow inhomogeneous distributions. Furthermore, we achieved a reduction of homogeneous linewidths by a factor of 2 after removing subsurface damage using oxygen plasma processing. These results not only give insights into the formation process of SiV− centers but also indicate a favorable processing method to fabricate shallow single quantum emitters in diamond perfectly suited for coupling to nanostructures on the diamond surface. We thank M. H. Metsch, A. Dietrich, and C. Osterkamp for experimental support and helpful discussions. This work was supported by DFG, Volkswagenstiftung, EU (Hyperdiamond, ERC Synergy Grant BioQ), and IQST. AK acknowledges the support from the BMBF/VDI (project Q.Link.X), the DFG (Project No. 398628099), and the European fund for the regional development (EFRE) program Baden-Württemberg.