High-purity single photons obtained with moderate-NA optics from SiV center in nanodiamonds on a bullseye antenna

Richard Waltrich,Elena S Steiger,Viatcheslav N Agafonov,Alexander Kubanek,Boaz Lubotzky,Valery A Davydov,Niklas Lettner,Konstantin G Fehler,Ronen Rapaport,Hamza Abudayyeh

doi:10.1088/1367-2630/ac33f3

Abstract

Coherent exchange of single photons is at the heart of applied quantum optics. The negatively-charged silicon vacancy center in diamond is among most promising sources for coherent single photons. Its large Debye–Waller factor, short lifetime and extraordinary spectral stability is unique in the field of solid-state single photon sources. However, the excitation and detection of individual centers requires high numerical aperture (NA) optics which, combined with the need for cryogenic temperatures, puts technical overhead on experimental realizations. Here, we investigate a hybrid quantum photonics platform based on silicon-vacancy center in nanodiamonds and metallic bullseye antenna to realize a coherent single-photon resource that operates efficiently down to low NA optics with an inherent resistance to misalignment.

Highlights

Coherent single photons are a key element for quantum technology such as quantum networks or quantum repeater where coalescence of indistinguishable photons is required to distribute quantum information over distance
The advantage of using such structures is that plasmonic modes have low mode volumes accompanied with low quality factors enabling spontaneous emission lifetime shortening and emission redirection over broad spectral ranges which can be used to enhance the zero phonon line (ZPL) emission of solid state emitters like the nitrogen vacancy center [14, 15] or recently the germanium vacancy center cite [16]
In order to coherently interact with individual SiV− center we focus on the most dominant spectral line centered at around 736.74 nm which is highlighted by the green square

Summary

Introduction

Coherent single photons are a key element for quantum technology such as quantum networks or quantum repeater where coalescence of indistinguishable photons is required to distribute quantum information over distance. On the other hand, achieving both emission lifetime shortening and high collection efficiency into low-NA optics with pure plasmonic structures require significant plasmon propagation lengths which in turn increase non-radiative recombination rates or quenching of the emission all together [17]. Another approach is to use pure dielectric antennas such as microcavities [18] and photonic crystals [19,20,21] that feature high radiative enhancement factors and low-loss [22, 23]. Integrated designs have been realized with all-diamond circular bullseye antenna with efficient, broadband collection from single NV center [30]

Methods

Results

Conclusion