Bright room temperature single photon source at telecom range in cubic silicon carbide

Abstract

Single-photon emitters (SPEs) play an important role in a number of quantum information tasks such as quantum key distributions. In these protocols, telecom wavelength photons are desired due to their low transmission loss in optical fibers. In this paper, we present a study of bright single-photon emitters in cubic silicon carbide (3C-SiC) emitting in the telecom range. We find that these emitters are photostable and bright at room temperature with a count rate of ~ MHz. Altogether with the fact that SiC is a growth and fabrication-friendly material, our result may be relevant for future applications in quantum communication technology.

Building Blocks for Quantum Network Based on Group‐IV Split‐Vacancy Centers in Diamond

“…For inter‐metropolitan fiber‐based quantum networks, telecom or near‐telecom wavelength emission is needed so as to take advantage of low‐loss transmission window granted by the silica optical fiber, which is probably the only financially affordable option for large‐scale deployment of long‐distance communication. The wavelength compatibility has been realized on multiple systems including emergent emitters in GaN, defects in SiC, doping of carbon nanotubes, and rare‐earth Er 3+ ions in solids, but not yet on split‐vacancy color centers, which require different techniques of frequency downconversion similar to those applied to semiconductor quantum dots . Secondly, mK cryogenic temperature operation on SiV − center is too costly and cumbersome for any practical usage of the long memory lifetime.…”

Silicon carbide color centers for quantum applications

“…A three-level system was observed for a single photon source of unassigned origin in the IR region in 3 C SiC [52], with a direct optical transition lifetime less than 1 ns, and a pronounced bunching effect with a fast decay (up to 20 s ns), as shown in figure 7. Due to room temperature operation and saturation count rate of 1 Mcts s −1 , this source is very appealing for application of single-photon sources for quantum communication and quantum cryptography, however, the unknown origin can limit its engineering.…”

“…In addition, some transition metal color centers such as Ti [45], V [45][46][47], and Mo [48]. On the right in red, color centers in SiC observed as single-photon sources with the maximum brightness observed in cts s −1 , among this the CAV [49,50], Si C [22], oxidation [22] and annealing [51] related and unknown, 3C IR emitters [52].…”

“…A single-photon source based on an emitter ranging from 1085÷1225 nm in 3C polytype has been discovered using superconducting single-photon detectors with a single-photon emission at 900 kcps s −1 , which is a record brightness at room temperature at this wavelength [52]. Due to the large variability of the emission the color center could not be associated with Ky5, as well DV can be observed as SPS only at low temperature and they are very weak (27 kcts s −1 at saturation).…”

“…The fitting parameters a, τ 1 and τ 2 of the antibunching curves as a function of excitation power. The red lines are the fitting of the data from[52] related to emission at 1200 nm in cubic SiC. Images reproduced from[52], Wang, Zhou, Wang, Rasmita, Yang, Li, von Bardeleben and Gao 2018 Bright room-temperature single-photon source at telecom range in cubic silicon carbide Nat.…”