Photoluminescence study of Vanadium in 4H- and 6H- Silicon Carbide

arXiv:2610.10781v1 Announce Type: new Abstract: Point defects with optically addressable spin states are a key building block for quantum networks, but few solid-state emitters combine a spin-photon interface with emission in the low-loss telecommunications band. Vanadium (V4+) defects in silicon carbide (SiC) meet this requirement, emitting zero-phonon lines (ZPLs) throughout the telecom O-band in both the 4H- and 6H-SiC polytypes while retaining an addressable electron and nuclear spin system [1,2]. Although the orbital and spin structure of these defects has been characterized in detail, the polarization selection rules have not been fully mapped experimentally. Here we present polarization-dependent photoluminescence (PL) measurements of vanadium ZPLs in 4H- and 6H-SiC at cryogenic temperature, of two scattering geometries: edge and face-on (emission wavevector perpendicular and parallel to the crystal c-axis, respectively). Emission from two of the four {\alpha} sites, ({\alpha}2 and {\alpha}3) and the 6H-SiC {\gamma} sites, are polarized parallel to the c-axis ({\sigma}-polarized), whereas emission from {\alpha}1 and {\alpha}4 are polarized perpendicular to the c-axis ({\pi}-polarized). Additionally, we report preliminary, lower signal measurements of the \b{eta} sites.