The negatively charged silicon vacancy center (Vs−) in silicon carbide (SiC) is an emerging color center for quantum technology. Limited information on its internal spin-optical dynamics hinders optimal operation and performance, especially in integrated quantum photonics. This paper establishes all relevant intrinsic spin dynamics of the Vs− center at the cubic lattice site (V2) in 4H-SiC through electronic fine structure modeling, including intersystem crossing and deshelving mechanisms. Spin-dependent measurements yield previously unknown spin-selective radiative and non-radiative decay rates. These rates are used to propose a realistic time-bin entangled multi-photon GHZ and cluster state generation protocol for integrated quantum photonics, showing that up to three-photon states are achievable using current nanophotonic cavity technology.

Di Liu, Florian Kaiser, Vladislav Bushmakin, Erik Hesselmeier, Timo Steidl, Takeshi Ohshima, Nguyen Tien Son, Jawad UI-Hassan, Öney O. Soykal, Jörg Wrachtrup