Negative spin-orbit bowing in semiconductor alloys

TLDR: The authors' self-consistent electronic-structure calculations for Ga(As,Sb) show very little s mixing in the VBM and an enhancement of ..delta../sub 0/. Intraband p-p coupling is shown to dominate the changes in ..d delta../ Sub 0/.

Abstract: Early measurements on many bulk III-V alloys showed that the spin-orbit splitting ${\ensuremath{\Delta}}_{0}$ at the valence-band maximum (VBM) was universally reduced relative to the average value of the end-point constituents. This led to the assumption, guiding much of the subsequent data analysis, that such alloys universally mix some conduction-band s character into the VBM (``interband coupling''), suppressing ${\ensuremath{\Delta}}_{0}$. Our self-consistent electronic-structure calculations for Ga(As,Sb) show very little s mixing in the VBM and an enhancement of ${\ensuremath{\Delta}}_{0}$. Intraband p-p coupling is shown to dominate the changes in ${\ensuremath{\Delta}}_{0}$.