Laser Writing and Spin Control of Near-Infrared Emitters in Silicon Carbide

Abstract

Near-infrared emission in silicon carbide (SiC) holds potential advantages to reduce losses in fiber-optic quantum communication, integrated quantum photonics, and quantum sensing based on single-photon emission and spin qubits. In this paper, we study the fluorescence emission of a direct femtosecond laser written array of color centers in SiC, followed by thermal annealing. We show that in high-energy laser writing pulse regions, a near-telecom O-band ensemble fluorescence emission is observed after thermal annealing, and it is tentatively attributed to the nitrogen vacancy center in SiC. Further in the low-energy laser irradiation spots after annealing, we fabricated a few divacancy PL5 and PL6 types and demonstrate their optical spin read-out and coherent spin manipulation (Rabi and Ramsey oscillations and spin echo). We show that direct laser writing and thermal annealing can yield bright near-telecom emission and allows the spin manipulation of the divacancy with above 1.6 μs coherence time at room temperature.