Vanadium spin qubits as telecom quantum emitters in silicon carbide

Abstract: Solid state quantum emitters with spin registers are promising platforms for quantum communication, yet few emit in the narrow telecom band necessary for low-loss fiber networks. Here we create and isolate near-surface single vanadium dopants in silicon carbide (SiC) with stable and narrow emission in the O-band (1278-1388 nm), with brightness allowing cavity-free detection in a wafer-scale CMOS-compatible material. In vanadium ensembles, we characterize the complex d1 orbital physics in all five available sites in 4H-SiC and 6H-SiC. The optical transitions are sensitive to mass shifts from local silicon and carbon isotopes, enabling optically resolved nuclear spin registers. Optically detected magnetic resonance in the ground and excited orbital states reveals a variety of hyperfine interactions with the vanadium nuclear spin and clock transitions for quantum memories. Finally, we demonstrate coherent quantum control of the spin state. These results provide a path for telecom emitters in the solid-state for quantum applications.