@article{oai:niigata-u.repo.nii.ac.jp:00002065, author = {Yamada, Takemi and Yamakawa, Youichi and Ono, Yoshiaki}, issue = {1}, journal = {Journal of Physics: Conference Series, Journal of Physics: Conference Series}, month = {Feb}, note = {The electronic state around a single vacancy in silicon crystal is investigated by using the Green's function approach. The triply degenerate charge states are found to be widely extended and account for extremely large elastic softening at low temperature as observed in recent ultrasonic experiments. When we include the LS coupling λSi on each Si atom, the 6-fold spin-orbital degeneracy for the V+ state with the valence +1 and spin 1/2 splits into Γ doublet groundstates and Γ8 quartet excited states with a reduced excited energy of O(λSi/10). We also consider the effect of couplings between electrons and Jahn-Teller phonons in the dangling bonds within the second order perturbation and find that the groundstate becomes Γ8 quartet which is responsible for the magnetic-field suppression of the softening in B-doped silicon.}, pages = {012228-1--012228-4}, title = {Effect of the spin-orbit interaction and the electron phonon coupling on the electronic state in a silicon vacancy}, volume = {200}, year = {2010} }