Silicon-vacancy Centers In Diamond Research Articles

Diamond defects cooperate via light.

Silicon-vacancy centers in diamond show single-photon switching and superradiance

Plasmon resonance enhanced temperature-dependent photoluminescence of Si-V centers in diamond

Temperature dependent optical property of diamond has been considered as a very important factor for realizing high performance diamond-based optoelectronic devices. The photoluminescence feature of the zero phonon line of silicon-vacancy (Si-V) centers in Si-doped chemical vapor deposited single crystal diamond (SCD) with localized surface plasmon resonance (LSPR) induced by gold nanoparticles has been studied at temperatures ranging from liquid nitrogen temperature to 473 K, as compared with that of the SCD counterpart in absence of the LSPR. It is found that with LSPR the emission intensities of Si-V centers are significantly enhanced by factors of tens and the magnitudes of the redshift (width) of the emissions become smaller (narrower), in comparison with those of normal emissions without plasmon resonance. More interestingly, these strong Si-V emissions appear remarkably at temperatures up to 473 K, while the spectral feature was not reported in previous studies on the intrinsic Si-doped diamonds when temperatures are higher than room temperature. These findings would lead to reaching high performance diamond-based devices, such as single photon emitter, quantum cryptography, biomarker, and so forth, working under high temperature conditions.

Photoluminescence of Si-vacancy color centers in diamond films grown in microwave plasma in methane-hydrogen-silane mixtures

The processes of the synthesis of silicon-doped microcrystalline diamond films on AlN and Si substrates in microwave plasma in “methane-hydrogen-silane” mixtures were studied. It is shown that the dependence of the photoluminescence (PL) line intensity of silicon-vacancy centers in diamond (λ = 738 nm) on the silane concentration in a gas mixture passes through a maximum at SiH4/CH4 concentrations of 0.1% for Si substrates and 0.6% SiH4/CH4 for aluminum nitride substrates. It was found that such nonmonotonic variation of the PL intensity with increasing silane concentration occurs despite the unchanged growth rate of the diamond film, its structure, and phase composition in the studied silane concentration SiH4/CH4 range of 0–0.9%.

Array of bright silicon-vacancy centers in diamond fabricated by low-energy focused ion beam implantation

Among promising color centers for single-photon sources in diamond, the negatively charged silicon-vacancy (SiV−) has 70% of its emission to the zero-phonon line (ZPL), in contrast to the negatively charged nitrogen vacancy (NV−), which has a broad spectrum. Fabricating single centers of useful defect complexes with high yield and excellent grown-in defect properties by ion implantation has proven to be challenging. We have fabricated bright single SiV− centers by 60-keV focused ion beam implantation and subsequent annealing at 1000 °C with high positioning accuracy and a high yield of 15%.

Indistinguishable photons from separated silicon-vacancy centers in diamond.

We demonstrate that silicon-vacancy (SiV) centers in diamond can be used to efficiently generate coherent optical photons with excellent spectral properties. We show that these features are due to the inversion symmetry associated with SiV centers. The generation of indistinguishable single photons from separated emitters at 5K is demonstrated in a Hong-Ou-Mandel interference experiment. Prospects for realizing efficient quantum network nodes using SiV centers are discussed.

Diamond and Silicon Get Entangled

Two silicon-vacancy centers in diamond can emit photons that are indistinguishable—suggesting they have potential as building blocks for a diamond-based quantum computer.

Plasmon-enhanced photoluminescence of Si-V centers in diamond from a nanoassembled metal–diamond hybrid structure

Using a facile top-down etching approach, a subwavelength-sized diamond pit structure infilled with semi-ellipsoidal gold nanoparticles was fabricated. The three-dimensional finite-difference time-domain simulations reveal strong localized surface plasmon resonance (LSPR) scattering and enhanced electric field exhibited by this hybrid nanoassembled metal–diamond-pit. Experimentally, with excitation at 633 and 830 nm close to the calculated LSPR wavelength, the photoluminescence (PL) intensities of the peak at 738 nm originating from the single photon source of silicon-vacancy centers in diamond were significantly enhanced by factors of ~100 and ~50, respectively, with respect to that from normal Si-doped diamond without the hybrid structure. By means of time-resolved PL measurements, the decay kinetic mechanisms of the plasmon-related PL enhancement were investigated and are discussed.

Electronic structure of the negatively charged silicon-vacancy center in diamond

The negatively-charged silicon-vacancy (SiV$^-$) center in diamond is a promising single photon source for quantum communications and information processing. However, the center's implementation in such quantum technologies is hindered by contention surrounding its fundamental properties. Here we present optical polarization measurements of single centers in bulk diamond that resolve this state of contention and establish that the center has a $\langle111\rangle$ aligned split-vacancy structure with $D_{3d}$ symmetry. Furthermore, we identify an additional electronic level and evidence for the presence of dynamic Jahn-Teller effects in the center's 738 nm optical resonance.

Photophysics of single silicon vacancy centers in diamond: implications for single photon emission

Single silicon vacancy (SiV) color centers in diamond have recently shown the ability for high brightness, narrow bandwidth, room temperature single photon emission. This work develops a model describing the three level population dynamics of single SiV centers in diamond nanocrystals on iridium surfaces including an intensity dependent de-shelving process. Furthermore, we investigate the brightness and photostability of single centers and find maximum single photon rates of 6.2 Mcps under continuous excitation. We investigate the collection efficiency of the fluorescence and estimate quantum efficiencies of the SiV centers.