The recent discovery of a two-dimensional electron (2DEG) gas at interfaces between nonpolar SrTiO₃ (STO) with other polar perovskites has lead to an enormous amount of research. Among this 2DEGs most interesting properties are two-dimensional superconductivity and ferromagnetism, sometimes concurrent. This study provides a starting point in understanding the reconstruction of bulk perovskite t₂[subscript g] bands near a surface or polar interface. First a symmetry constrained [k arrow] · [p arrow] model is developed for an arbitrary pseudocubic bulk perovskite. This [k arrow] · [p arrow] model is applied to studies of bulk STO under external strain and to the Shubnikov - de Haas effect in lightly doped STO to high magnetic fields. Then a simplified electronic structure model is developed for surfaces and interfaces. This model includes non-linear and non-local screening effects by a single polar lattice mode. Generalization of the lattice screening model is discussed. Bonding within a single perovskite layer is then investigated further to understand Rashba interactions and their connection with microscopic material parameters. Next the optical conductivity of quantum confined t₂[subscript g] bands is investigated. Finally some possible future work based on the ideas developed in this thesis are explained. / text
| Identifer | oai:union.ndltd.org:UTEXAS/oai:repositories.lib.utexas.edu:2152/21599 |
| Date | 17 October 2013 |
| Creators | Khalsa, Guru Bahadur Singh |
| Source Sets | University of Texas |
| Language | en_US |
| Detected Language | English |
| Format | application/pdf |
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