Speaker
Description
Group-IV color centers in diamond are well known for their suitability as nodes within quantum networks due to their excellent spin and optical coherence. The tin-vacancy center (SnV-) in particular shows Fourier limited linewidths, a small inhomogeneous distribution of emission wavelengths, and excellent long-term spectral stability [1-3]. The latter two of which have been observed for deep implanted emitters, after high pressure high temperature (HPHT) annealing to reduce lattice damage.
However, these SnV-'s in bulk diamond are limited to a collection efficiency of only a few percent [4], insufficient for most applications. This may be improved through redirection of light towards collection optics. Further enhancement of the collected photon count rate can be obtained through Purcell enhancement in nanophotonic structures such as circular Bragg gratings. In these structures SnV- centers are always close to the diamond surface. However, HPHT annealing is damaging to the diamond surface, and so to benefit from these enhancements other ways of stabilizing emitters must be explored.
Here we present a statistical analysis of room temperature measurements on the effect of surface terminations on shallow (20 - 100 nm implantation depth) SnV- centers annealed under vacuum at 1200°C. A thermally oxidised sample, a hydrogen and hydroxyl group terminated sample are compared to a tri-acid cleaned sample. It is seen that compared to the tri-acid sample, the remaining all show improvements in charge state stability and reductions to background fluorescence, with the long term stability of both hydrogen and hydroxyl group terminations surpassing that of the thermal annealing. We intend to measure these samples also at < 2 K.
[1] M. Trusheim, et al., Phys. Rev. Lett. 124(2) (2020), 023602, [2] J. Görlitz, et al., npj Quantum Inf 8(1) (2022), 45, [3] Y. Narita, et al., Phys. Rev. Applied 19(2) (2023), 024061, [4] E. Janitz, et al., Optica 7(10) (2020), 1232-1252.
