Optical Properties of Vacancy-related Color Centers in SiC
Sprache des Vortragstitels:
Defects in solids for quantumtechnologies
Sprache des Tagungstitel:
Vacancy-related color centers insilicon carbid implement quantum bits for applications likequantum sensing or single photon emitters. The fundamentaloptical transition and competing spin-selective, non- radiativetransitions via intermediate low-spin states are pivotal partsof the mechanism underlying qubit applications. Opticalionization will produce other inactive charge states of thequbit. The ability to control and deliberately switch the chargestate is pivotal for applications and has recently been exploredexperimentally for qubit centers in SiC [1, 2]. However, thecharge states actually involved in the switching and theiroptical properties are often not clear. Furthermore theelectrical detection of spin states, as demonstrated for theNV-center in diamond, involves emission of defect spins intothe conduction or valence band in a two-photon process. How theoptical ionization yield and the spin contrast depend on thephoton energy is an open question. Here we investigate theoptical properties and ionization of vacancay-related colorcenters in SiC within the frame work of the CI-CRPA approach. This approach allows for the description of highlycorrelated multiplet states and gives access to thespin-selective, non-radiative transitions or as shelving statesand determine the spin contrast. We address ionizing single andtwo-photon processes relevant for optical charge-state switchingand electrical detection of the spin states. Our results revealdestinct photon-energy dependent ionization cross sectionsregarding electron and hole emission. This determines the chargestate yielded by the ionization.