Strained empirical pseudopotential generation from hybrid density functionals: GaAs, InAs,GaSb, InSb
Author
Çakan, Aslı
Advisor
Bulutay, Ceyhun
Date
2015-08Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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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.
Keywords
Deformation potentialAnisotropic strain
Electronic band structure
Empirical pseudopotential method
Density functional theory
Hybrid functionals