Theory of d₀ perovskites and their heterostructures

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.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Physics

Grantor

The University of Texas at Austin

Year dc:date.issued

2013

Author dc:creator

• Khalsa, Guru Bahadur Singh

Advisor dc:contributor.advisor

• MacDonald, Allan H.

• Perovskites
• 2DEG
• Quantum confinement

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/2152/21599

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/21599