The field of Condensed Matter Physics and Materials Science integrates the knowledge and tools of chemistry and physics with the principles of engineering to understand and optimize the behavior of materials, as well as to create new and improved materials to help fulfill the missions of the Department of Energy.
Condensed-Matter Physics & Materials Science Seminar
"The first-principles study of structural, electronic, and magnetic properties of strongly correlated materials: DFT+DMFT approach."
Presented by Hyowon Park, University of Illinois
3 pm, Bldg. 734, ISB Conference Room 201 (upstairs)
Thursday, August 25, 2016, 3:00 pm
Hosted by: ''Neil Robinson''
Strongly correlated materials including transitional metal oxides and heavy fermion materials exhibit novel structural, electronic, and magnetic properties. The first-principles study of these unusual properties requires a theoretical description that goes beyond density functional theory to treat strong correlation effects properly. In this talk, I will show that the density functional theory plus dynamical mean field theory (DFT+DMFT) method enables realistic and quantitative calculations of those properties in good agreement with experimental spectroscopic measurements. First, I will clarify the nature of the insulating phase in bulk rare-earth nickelates using DFT+DMFT and determine the structural and metal-insulator phase diagram. I will also present DFT+DMFT results of structural and electronic properties in artificially structured LaNiO3/LaAlO3 superlattices under strains. Calculation results of layer-resolved orbital polarization will be compared to recent X-ray absorption spectroscopy data and analyzed in terms of structural and quantum confinement effects. Finally, I will show the momentum and frequency dependent magnetic excitation spectra in CePd3 computed using DFT+DMFT and explain that the calculated spectra based on realistic band excitations are in good agreement with the inelastic neutron scattering data measured in this material.
Explores the electronic structure and electrodynamics of topological insulators and strongly correlated electron systems, with particular attention to emergent phenomena, such as superconductivity and magnetism, using angle-resolved photoemission (ARPES) and optical spectroscopy.
Studies the role of antiferromagnetism in high-temperature superconductors. The interaction of charge carriers with magnetic moments is of critical importance but remains a challenge to understand. .
Carries out basic studies of the structural, electronic and magnetic properties of condensed matter systems using synchrotron-based x-ray scattering techniques. .
Conducts basic research over a wide swath of theoretical physics, ranging from strongly correlated electrons to first principle electronic structure theory.
Studies both the microscopic and macroscopic properties of complex and nano-structured materials with a view to understanding and developing their application in different energy related technologies
Addresses key open questions in HTS physics such as the dimensionality of the HTS phenomenon, the spin and charge of free carriers, the nature of the superconducting transition, the role of charge stripes (if any) in the HTS state, the nature of the overdoped metallic state, and more.
Span a wide range of quantum matter systems, including superconductors, superfluids, supersolids, electronic liquid crystals, topological insulators superconductors & superfluids, heavy fermions, and spin liquids. Throughout, the focus is on development of innovative techniques and approaches to each problem.
Utilizes advanced electron microscopy techniques to study nanoscale structure and defects that determine the utility of functional materials, such as superconductors, multiferroics, and other energy related systems including thermoelectrics, photovoltaics, and batteries.
The Condensed Matter Physics and Materials Science Department is part of Brookhaven National Laboratory's Energy Sciences Directorate.