9612304 Henley This grant supports work on a variety of cutting-edge problems in material magnetism. In a continuation of a successful program, the current project includes: (1) discrete spin models in 2 dimension with interface representations, (2) Application of semiclassical (path integral) approaches to spatially finite spin systems and (3) Spin order in highly frustrated Heisenberg antiferromagnets. These projects involve use of a combination of analytical skills and numerical methods. The two specific projects where the original problems are long- standing questions and which are expected to be resolved during the present grant using some of the techniques developed by this PI are: the ground state of an S=1/2 quantum antiferromagnet on a triangular lattice and properties of SrCrGaO, a magnetic material with a two layer Kagome sandwich structure. %%% This grant supports work on a variety of problems in material magnetism that are both highly complex in that they remain unsolved (after a half century of careful search for solutions) so far and are derived from state of the art questions in material magnetism. There are magnets where the interaction between individual spins (the constituent unit at the atomic level) is strong but highly competitive and "frustrated" in the sense that the neighboring spins demand conflicting orientation for a specific spin. These materials become magnetic, if at all, only at very low temperatures and then they often have strong anomalous properties. This project is a theoretical study of the experimental properties of frustrated magnets that have been reported recently. ***
