9512856 Ying A U.S.-Brazil collaborative research effort will be carried out by See-Chen Ying, John Kosterlitz, and Tapio Ala-Nissila of Brown University and Enzo Granato of the Instituto Nacional de Pesquisas Espaciais in Sao Paulo to study the transport properties of adsorbed layers and superconducting Josephson-junction arrays, considering both linear and nonlinear regimes. The investigators will apply a two- dimensional version of the Frenkel-Kontorova model to understand sliding friction of an adsorbed layer under a steady external force in the plane. In addition, they will use numerical simulations to study the effect of pinning in the melting of Abrikosov vortex lattices in the context of a Josephson-junction array in a magnetic field. The work will deepen our understanding of one of the growing fields of condensed matter science. The U.S team brings an excellent record of research in surface diffusion and Josephson-junction arrays, while the Brazilians contribute considerable expertise in numerical simulations. The international collaboration, supported in Brazil by CNPq, will benefit both sides as well as the field in general. ****
