Optical Properties of Vanadium in 4 H Silicon Carbide for Quantum Technology

Light emission stemming from V impurities in $4H$-SiC is recorded at 1.28 and 1.33 μm, in the telecommunication O band, which gives hope for the creation of efficient single-photon sources in existing telecommunication networks, ultimately paving the way for secure long-range quantum communication networks. Combined with the available electronic and nuclear degrees of freedom, vanadium presents all of the required ingredients for a highly efficient spin-photon interface. These V centers are reminiscent of the Mo defect in SiC and the Si-V complex in diamond, but work at practical wavelengths for telecommunication.