Scalable Quantum Photonics with Single Color Centers in Silicon Carbide

Abstract

Silicon carbide is a promising platform for single photon sources, quantum bits (qubits), and nanoscale sensors based on individual color centers. Toward this goal, we develop a scalable array of nanopillars incorporating single silicon vacancy centers in 4H-SiC, readily available for efficient interfacing with free-space objective and lensed-fibers. A commercially obtained substrate is irradiated with 2 MeV electron beams to create vacancies. Subsequent lithographic process forms 800 nm tall nanopillars with 400-1400 nm diameters. We obtain high collection efficiency of up to 22 kcounts/s optical saturation rates from a single silicon vacancy center while preserving the single photon emission and the optically induced electron-spin polarization properties. Our study demonstrates silicon carbide as a readily available platform for scalable quantum photonics architecture relying on single photon sources and qubits.

Room-temperature polarized spin-photon interface based on a semiconductor nanodisk-in-nanopillar structure driven by few defects

“…Given that the etched DiP has a smaller emitting volume than the MQWs and it additionally suffers from enhanced non-radiative surface recombination associated with the unpassivated NP surface, the observed stronger PL from the DiP array clearly demonstrates a better light absorption and/or extraction efficiency than the planar MQWs. This finding is consistent with the PL results from other semiconductors with similar structures 43,44 . The measured PL intensity, I PL , is affected by multiple factors 45 ,where α in ( α out ) is the in (out)-coupling coefficient which determines the absorption (extraction) efficiency of light.…”

Silicon carbide color centers for quantum applications

“…Both V2 and V1 lines in the 4H polytype has been proven for optical coherent spin control. In particular, the V2 line has been mostly studied as qubit with ZFS of 70 MHz, the V2 maximum ODMR signal (|ΔPL/PL|) by off-resonant optical excitation is 1.8% when the V2 center is embedded in nanopillars [18] (0.4% when in bulk material). The largest PL intensity for V2 is 10 kcps s −1 without a solid immersion lens using a Si detector with 20%-30% quantum efficiency [78] and 40 kcps with a solid immersion lens [69].…”

“…Due to the influence of their higher concentration or even formation after thermal treatment in the presence of Oxygen, which favors the oxide formation, these defects were also assigned to oxygen-related defects at the sample surface [22]. To determine if there is an incorporation of oxygen in these surface emitters, SPSs were fabricated using 18 O isotopes as oxidants. The emission spectra for the 18 O SPSs tended to be blue shifted, slightly narrower peak widths, and higher intensities if compared to natural oxygen annealing indicating that oxygen was incorporated into the defects attributed to the surface emitters [130].…”

“…Some of the SiC intrinsic and extrinsic point defects hold competitive properties that, if integrated with the material scalability and control, could advance the current state of the art.SiC offers an alternative platform for integration of quantum systems in large scale wafers as well as suitability for nanofabrication and great potentials for integrated quantum photonics [2], owing to its secondorder nonlinearity, low two-photon absorption, and optical transparency. However, challenges are still in both the material fabrications for integrated photonics and the color centers' generation and control [18]. An even more exciting field for quantum devices in SiC [19] can be found in its electrical excellent properties and electrical device fabrication, that is by far more established than photonics, as SiC is used in high power electronics [20] and in metal-oxide-semiconductor field-effect transistor (MOSFET) [21].…”

Simulation of the Growth Kinetics in Group IV Compound Semiconductors

“…The crystal growth of group IV materials is a topic of extreme technological interest due to the importance of these materials for current and future technologies (including quantum technologies, see e.g., ref. ). In the case of compound semiconductors and in particular for SiC, the growth of a high‐quality material is particularly challenging due to the meta‐stability of different crystal symmetries (polytypes) in the usual growth conditions .…”