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arXiv · 2010.15475

Single germanium vacancy centres in nanodiamonds with bulk-like spectral stability

Mackrine Nahra·Daniel Alshamaa·Regis Deturche·Valery Davydov·Ludmila Kulikova·Viatcheslav Agafonov·Christophe Couteau
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Abstract

Motivated by the success of group IV colour centres in nanodiamonds (NDs) for hybrid technology requiring a single photon source, we study single germanium-vacancy (GeV$^-$) centres in NDs at room temperature with size rangingfrom 10 to 50 nm and with remarkable spectral properties. We characterize their zero-phonon line (ZPL), study their internal population dynamics and compare their emission properties in the framework of a three level model with intensity dependent de-shelving. Furthermore, we characterize their lifetime, polarization and brightness. We find amaximum photon emission count rate of 1.6 MHz at saturation. We also report a polarization visibility of 92% from the fluorescence light, which potentially makes GeV$^-$ centres good candidates for quantum key distribution (QKD)requiring polarized single photons. We show that the GeV$^-$ in NDs presented in this work have a comparable spectral stability compared to their bulk counterpart which is needed for future applications using NDs.

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Mackrine Nahra, Daniel Alshamaa, Regis Deturche, Valery Davydov, Ludmila Kulikova, Viatcheslav Agafonov, Christophe Couteau. 2020-10-29. Single germanium vacancy centres in nanodiamonds with bulk-like spectral stability. https://doi.org/10.1116/5.0035937

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