Multiple intrinsically identical single-photon emitters in the solid state

Abstract

Emitters of indistinguishable single photons are crucial for the growing field of quantum technologies. To realize scalability and increase the complexity of quantum optics technologies, multiple independent yet identical single-photon emitters are required. However, typical solid-state single-photon sources are inherently dissimilar, necessitating the use of electrical feedback or optical cavities to improve spectral overlap between distinct emitters. Here we demonstrate bright silicon vacancy (SiV À ) centres in low-strain bulk diamond, which show spectral overlap of up to 91% and nearly transform-limited excitation linewidths. This is the first time that distinct single-photon emitters in the solid state have shown intrinsically identical spectral properties. Our results have impact on the application of single-photon sources for quantum optics and cryptography.

High quality-factor optical nanocavities in bulk single-crystal diamond

“…Finally, to utilize the broadband nature of diamond, we explored the potential of our angled-etching approach to realize optical cavities operating in visible and near-infrared. Visible diamond cavities are of great interest for the enhancement of emission properties of diamond's luminescent defects, such as the negatively charged silicon vacancy centre (zero phonon line at lB737-nm) [34][35][36] and, in particular, the negatively charged nitrogen vacancy centre (NV À , with zero phonon line at lB637-nm and phonon side band up to nearly 800-nm) [37][38][39] . To realize visible band optical cavities in diamond, we scaled down all design parameters by a factor of B2.5, and no additional modelling was needed.…”

Cavity-Funneled Generation of Indistinguishable Single Photons from Strongly Dissipative Quantum Emitters

“…For solid-state QE emitting photons at room temperature such as color centers, quantum dots or organic molecules, pure dephasing rates are typically several orders of magnitude larger than the population decay rate (typically ranging from 3 to 6 orders of magnitude) [12,14,21,22,24,[26][27][28][29]31]. Hence the intrinsic indistinguishability given by Eq.…”

“…On the other hand, sources based on single solid-state quantum systems have been greatly developped in the last decade, as they hold the promise to combine indistinguishable, on-demand, energy-efficient, electrically drivable and scalable characteristics. However, except at cryogenics temperature, solid-state systems emitting single-photons are subject to strong pure dephasing processes [21][22][23][24][25][26][27][28][29], making them at first view inappropriate for quantum applications requiring photon indistinguishability.A two-level quantum emitter (QE) coupled only to vacuum fluctuations should emit perfectly indistinguishable photons. However, as soon as pure dephasing of the QE occurs, the degree of indistinguishability of the emitted photons is reduced to [30]…”

Coherent control of a strongly driven silicon vacancy optical transition in diamond

“…This shows that no apparent excitation induced dephasing is observed. This can be partially explained by the weak electronphonon coupling of the SiV and the reduced sensitivity to fluctuating electric fields within the diamond lattice [8][9][10][11][12] . Robust T 2 , combined with the frequency stability and efficient generation of SiV single photons, shows the feasibility of SiV as an efficient and coherent single photon source.…”

“…The silicon vacancy (SiV) centre in diamond is one potential candidate, with B70% of the photons emitted into the ZPL 6,7 . Different SiV defects exhibit intrinsically identical spectral properties in low-strain bulk diamond 8,9 and nearly transform-limited linewidth [9][10][11][12] . SiV spin coherence times are in the range of B40 ns at cryogenic (4 K) temperatures 13,14 .…”