This award will support Professor Malvin Kalos of New York University in a research collaboration with Professor L. Reatto of the Universita degli Studi di Milano, Italy. The investigators intend to continue their studies in the computational quantum mechanics of solid and liquid helium. Our current understanding of low density solid and of the liquid-solid phase transitions of highly quantum systems is still incomplete. Both experimentally and theoretically, such transitions are strongly affected by quantum effects. Using variational calculations and a Green's function Monte Carlo (GFMC) method, the investigators have obtained important results about liquid-solid transitions and about basic properties of two-dimensional liquid and solid helium which will be extended through this collaboration. The proposed work is complementary: the U.S. side will contribute the methodology of computational many-body theory, especially as it applies to quantum problems in their ground states and finite temperature. The Italian side will work on theoretical and analytical results based on the numerical results obtained by the U.S. researchers. Given this degree of complementarity, it is likely that the collaboration will lead to increased understanding of quantum effects of liquid-solid transitions and materials.
