First-principles prediction of the negatively-charged nitrogen-silicon-vacancy center in cubic silicon carbide

We performed density-functional theory calculations to study the energetic stability and the electronic structures, of negatively-charged nitrogen-silicon-vacancy center (N-V(Si))(-) in cubic silicon carbide (3C-SiC). We show that the (N-V(Si))(-) center is energetically preferable in n-type 3C-SiC and possesses a stable (3)A(2) ground state and doubly degenerated (3)E excited states. The (N-V(Si))(-) centers prefer to couple weakly in an antiferromagnetic way, triggered by superexchange between them. Our work indicates that 3C-SiC may be an economical candidate material to achieve a solid state qubit operation beyond diamond. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3471813]