Access to the spin & photo physics of a prototypical color center via quantum embedding theory

Prototypical color centers in semiconductors, such as the NV-center in

diamond or vacancy-related defects in silicon carbide, were identified

as promising candidates for the implementation of quantum

applications such as quantum sensing or quantum networks. Their

coupled electron spins feature correlated high/low-spin states that

enable spin-selective manipulation e.g. via photo excitation, magnetic

fields or mechanics. Advanced quantum embedding of a color center via

a hamiltonian with an effective screened Coulomb interaction and a

solver based on configuration interaction [1] has provided access to a

quantitative understanding of the involved physics and opens access to

theory-based qubit engineering. Our insight into the spin-selective

optical cycle and photo ionization of the silicon vacancy in SiC [2]

demonstrates this. Our recent developent enables the calculation of

orbit-strain/spin-strain as well as hyperfine coupling parameters.

We will address implication for the optical cycle.

[1] M. Bockstedte et. al., npj Quantum Materials 3, 31 (2018).

[2] T. Seidl et al., Nat. Commun. 16, 4669 (2025).