This award supports theoretical research and education on the quantum theory of localized magnetic moments in diverse electronic environments in solids. Specific areas of research include the physics of geometric frustration of quantum magnetism in insulating materials and the interplay between possibly frustrated inter-moment exchange and coupling between local moments and conduction electrons in metallic materials. Emphasis will be on understanding low temperature phenomena where quantum mechanical effects dominate. The PI aims to clarify the nature of the ground states and low energy excitations suggested by experiments or numerical calculations on several low-dimensional insulating frustrated quantum magnets. Field theoretical methods will be developed with an aim to obtaining physical insight. The PI will explore whether frustrated quantum magnets display excitations with fractional quantum numbers. The PI seeks to bridge the gap between theory and experiments in this active area of condensed matter physics. The PI will also study Kondo lattice models for metallic systems with localized magnetic moments, for example LiVO. Various phenomena discovered in these systems originate in the competition between possibly frustrated magnetic exchange between the local moments and the interaction between the local moments and the conduction electrons. This award also supports education at the graduate level in advanced theoretical condensed matter physics. The PI plans to involve undergraduate students in the research. %%% This award supports fundamental theoretical condensed matter physics research on phenomena that arise from geometrical frustration of quantum magnetic materials and the interaction between magnetic moments localized on particular atomic sites with itinerant conduction electrons. Geometrical frustration occurs when the interactions between magnetic moments cannot be simply satisfied because of the geometrical arrangement of the moments on the crystal lattice. This is fundamental research in an active and challenging area that involves strongly correlated electron materials including heavy fermion materials and quantum magnets like Cs2CuCl4. Research in this area has revealed subtle and beautiful phenomena in condensed matter physics and provides the intellectual foundation for future materials and device technologies. This award also supports education at the graduate level in advanced theoretical condensed matter physics. The PI plans to involve undergraduate students in the research. ***
