Strained empirical pseudopotential generation from hybrid density functionals: GaAs, InAs,GaSb, InSb

Abstract

Self-assembled quantum dots composed of III-V compounds receive considerable attention due to their potential applications on spintronics and quantum informa- tion processing. Here, lattice mismatch between two materials causes a remark- able strain and this subsequently affects not only carriers but also nuclear spins due to electric quadrupole interaction. In this thesis, the behavior of electronic band structure and deformation potentials under various strains are investigated in the family of semiconductors consisting of InAs, GaAs, InSb and GaSb. Com- putations are performed using semi-empirical pseudopotential method (EPM) by generating a new set of strain-compliant pseudopotentials. In order to both lead and validate EPM calculations, density functional theory based on hybrid functionals has been employed. Our results on hydrostatic and shear strain de- formation potentials obtained by either technique are in very good agreement with the experimental data. We demonstrate that the newly proposed empirical pseudopotentials perform well around band edges under anisotropic crystal de- formations. This paves the way for large-scale electronic structure computations involving lattice mismatched constituents.