CAREER: Discovery and Characterization of Strongly Correlated Topological Materials

Washington University, Saint Louis MO

Investigators

Abstract

Non-technical Abstract: The development of new quantum materials is driven by two concepts, band structure topology and strong electronic correlations. Due to the long-standing challenge of calculating band structures of strongly correlated systems, the interplay of these two central themes of condensed matter physics has not been actively investigated. The research team is studying novel topological properties of strongly correlated electronic systems, aiming for yet-unknown phases, transitions, and functionalities. Based on a practical design principle developed by the research team, this project accelerates the theoretical unification of strong correlation physics and band structure topology, greatly enhances our understanding of quantum materials, further expands the horizon of topological phases. These might lead to promising applications for future technologies. A comprehensive education and outreach plan is incorporated to transmit the core knowledge of quantum physics and quantum materials. Technical Abstract: Due to the interplay between Coulomb repulsion and kinetic degrees of freedom of electrons, the prediction of topological properties in strongly correlated materials represents a theoretical challenge. The research team is investigating exotic phases and materials originating from the convergence between strong correlations and band structure topology. The research team has developed a practical design principle to guide the systematic discovery of novel strongly correlated topological materials, which is specifically realized by combining (1) strong correlations induced by Kondo hybridization, (2) band crossing enforced by non-symmorphic crystal symmetries, and (3) large spin orbital coupling in uranium systems. The research team will utilize single crystal synthesis, electric and thermal transport measurement, first principle calculations and photoemission spectroscopy to identify new systems with non-trivial topology originating from strong correlations and discover new emergent low energy excitations. Specific goals of the project include: (1) to reveal the the mechanism by which Kondo hybridization gives rise to nontrivial topological bands and its contribution to the anomalous Hall effect; (2) to discover novel topological states induced by strong correlation in the 2D limit; and (3) to understand the unusual field dependence of the anomalous Hall effect in Kondo-Weyl semimetals. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.