Strong Correlations in Chiral Electron Systems

TECHNICAL SUMMARY

This award supports combined theoretical research, education, and outreach to pursue the consequences of spin-orbit coupling in various materials through a chiral Fermi liquid theory. The research part of the proposal will explore possibilities of new phases of electronic matter in two-dimensional electron systems with strong spin-orbit coupling, focusing on electron and hole gases in gallium-aluminum-arsenide heterostructures, surface states of oxides, states at oxide interfaces, and three-dimensional topological insulators. The main thrusts of the project include

+ developing the general theory of chiral Fermi liquids;

+ applying this theory to three main archetypes of chiral Fermi liquids: systems with linear and cubic spin-orbit couplings, and Dirac fermions on the surface of topological insulators;

+ identifying and classifying possible novel phases resulting from the interplay between the electron-electron and spin-orbit interactions in these systems;

+ analyzing ferromagnetic order of nuclear spins coupled by an indirect interaction via heavy holes in p-gallium arsenide quantum wells;

+ developing a theory of novel collective modes in chiral Fermi liquids and proposing experiments for detecting these modes;

+ understanding the interplay between superconductivity and spin-orbit coupling in a 2D superconductor at lanthanum aluminate/strontium titanate interfaces.

This award also supports educational and outreach activities that will address diverse audiences of graduate and undergraduate students at the University of Florida, as well as a broader community of STEM teachers via the FloridaTeach program. Using the already existing framework of the advanced multi-faculty course at the UF Department of Physics, the PI will develop month-long courses of lectures on the topics relevant to this project for graduate students. Educational materials for these lectures will be available for a broader audience of graduate students and researchers via the UF Physics website. At the undergraduate level, the PI will involve participants of the existing REU program in some of the research projects related to this proposal. Finally, the PI will deliver popular lectures on advances in nanoscience to Florida STEM teachers.

NONTECHNICAL SUMMARY

This award supports theoretical research that crosscuts two very active research areas in materials research. The first one is the field of strongly correlated electron systems and quantum phase transitions in itinerant electron systems. The main goal of this field is to understand the mechanisms by which the electrons in a many-electron system choose to organize themselves into an ordered state, such as magnetism over a liquid-like state. The second one is the field of semiconductor spintronics and quantum computation with spin qubits. The main physical ingredient of this field is correlated dynamics of just a few or many electrons along with their spins. There are interesting 'overlap regions' between these two areas, and the PI aims to investigate them. The results will help to improve our understanding of fundamental physics in both areas, and thus will be of interest to a broader community. The universal language of symmetry-based phenomenology employed by the theory of Fermi liquids should be equally familiar to large communities of researchers working in strongly correlated electron systems and in spintronics/quantum computation. Training of graduate students will prepare them not only to life in academia but would also give them useful problem-solving skills that can be used outside of academia. The PI's group has a strong record for placement of PhD students some of whom made successful academic careers and some chose equally successful careers in industry.