| AVS 65th International Symposium & Exhibition | |
| Electronic Materials and Photonics Division | Tuesday Sessions |
| Session EM+2D+AN+MI+MP+NS-TuA |
| Session: | Solar/Energy Harvesting and Quantum Materials and Applications |
| Presenter: | Samuel Carter, U.S. Naval Research Laboratory |
| Authors: | H.B. Banks, National Research Council Postdoc residing at the Naval Research Laboratory O. Soykal, Sotera Defense Solutions, Inc, residing at the Naval Research Laboratory S.P. Pavunny, U.S. Naval Research Laboratory R.L. Myers-Ward, U.S. Naval Research Laboratory D.K. Gaskill, U.S. Naval Research Laboratory S.G. Carter, U.S. Naval Research Laboratory |
| Correspondent: | Click to Email |
Defects in wide bandgap materials have generated substantial interest as promising systems for quantum information and quantum sensing due to bright, stable optical emission that is often coupled to long-lived spin states. One promising defect system is the silicon monovacancy in SiC (VSi), which has a spin-3/2 ground state that can be optically polarized and maintain long spin coherence times even at room temperature. SiC is an attractive material in terms of mature growth and fabrication technology and also has a low natural abundance of nuclear spins, which reduces spin dephasing. While significant work has been performed to study the spin properties of VSi for ensembles and even single defects, the optical properties and their connection to the spin system are less developed. Here we report on high resolution optical spectroscopy of single VSi defects, specifically V2 defects, at low temperatures. Using laser excitation spectroscopy, the zero phonon line (ZPL) transitions corresponding to the ms=±1/2 and ms=±3/2 spin states are resolved, with a linewidth down to 70 MHz and a splitting of 1 GHz. While there is significant variation in the transition energies from one defect to another, the splitting of these lines is very uniform. We also find that emission from the V2 defect under resonant excitation of these lines rapidly decays on two very different timescales. Slow decay on a 10 ms timescale is attributed to photoionization of VSi and can be prevented by periodically exciting the defect with a second laser at 745 nm. Fast decay on a μs or shorter time scale occurs due to a combination of intersystem crossing and spin polarization of the ground state. A significant difference in the decay rates of the two transitions is observed, which gives rise to spin-dependent photoluminescence intensity and non-resonant optical spin polarization. These results further our understanding of the connection between the optical and spin properties of this defect system that are necessary to optically control and readout the spin system as well as to develop a spin-photon quantum interface.