Type
Text
Type
Dissertation
Advisor
Aronson, Meigan C | Liu, Mengkun | Parise, John B | Kotliar, Gabriel | Allen, Philip B.
Date
2015-12-01
Keywords
Condensed matter physics
Department
Department of Physics
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76653
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Electron-electron interactions must be considered to understand the electronic ground states of many crystalline solids. The work presented here addresses the effects of electronic correlation in several manganese pnictide compounds. These results contribute to our understanding of the conditions under which high temperature superconductivity and spin liquid behavior can occur. First, we find that the intra-atomic Hund’s coupling between electrons is crucial for the stabilization of an insulating ground state in LaMnPO and BaMn$_2$As$_2$, which are isostructural to the parent compounds of the high temperature iron-based superconductors. Second, we find that competing inter-atomic exchange interactions frustrate the long range magnetic order in the corrugated honeycomb lattice compound CaMn$_2$Sb$_2$. Finally, we find signatures of an orbitally selective Mott phase in LaMn$_x$Sb$_2$. To arrive at these results, we performed and analyzed inelastic neutron scattering, x-ray and neutron diffraction, transport, specific heat and magnetization measurements on bulk single crystals and powders that we synthesized. We also collaborated extensively with groups that performed optical spectroscopy measurements on single crystals that we provided and electronic structure calculations on input crystal structures that we provided. | Electron-electron interactions must be considered to understand the electronic ground states of many crystalline solids. The work presented here addresses the effects of electronic correlation in several manganese pnictide compounds. These results contribute to our understanding of the conditions under which high temperature superconductivity and spin liquid behavior can occur. First, we find that the intra-atomic Hund’s coupling between electrons is crucial for the stabilization of an insulating ground state in LaMnPO and BaMn$_2$As$_2$, which are isostructural to the parent compounds of the high temperature iron-based superconductors. Second, we find that competing inter-atomic exchange interactions frustrate the long range magnetic order in the corrugated honeycomb lattice compound CaMn$_2$Sb$_2$. Finally, we find signatures of an orbitally selective Mott phase in LaMn$_x$Sb$_2$. To arrive at these results, we performed and analyzed inelastic neutron scattering, x-ray and neutron diffraction, transport, specific heat and magnetization measurements on bulk single crystals and powders that we synthesized. We also collaborated extensively with groups that performed optical spectroscopy measurements on single crystals that we provided and electronic structure calculations on input crystal structures that we provided. | 133 pages
Recommended Citation
McNally, Daniel Edward, "Strong Electronic Correlations in Manganese Pnictide Compounds" (2015). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2539.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2539