9705513 Beauchamp This is a Research Planning Grant for a new female faculty to study the Bose glass. The Bose glass is a system of superconducting vortices localized in a disordered columnar defect lattice, is described by the same Hamiltonian as the Coulomb glass, a system of localized charge carriers in a doped. The ground state of these systems, which determines whether they are conducting or insulating, depends in a complicated manner on the relative strengths of the particle- particle and particle-potential interactions. In the Bose glass, disorder can be controlled by creating the columnar defects in thin superconducting films using electron-beam lithography, and particle interactions can be controlled simply by changing the applied magnetic field. Using this model Bose glass system, this proposed research aims to elucidate the effects of independent variation of particle interactions and disorder on both the static configuration and the dynamic motion of the particles. Since such control over disorder and interaction is not possible in the Coulomb glass, the results of this research will provide valuable feedback for the theoretical understanding of these systems. Furthermore, the results of this research will deepen our understanding of vortex pinning in those high temperature superconductors that have disordered columnar defect lattices produced by heavy-ion bombardment. %%% Although physicists have been successful in developing a detailed understanding of electronic and magnetic properties of a wide range of materials, disorder and strong interparticle interactions in some materials has encumbered such a detailed understanding. The present research will focus on the role of disorder and interparticle interactions in a system of magnetic flux tubes, called vortices, in superconducting thin films with intentionally fabricated defects. The defects will be created and controlled using electron-beam lithography, and vortex interactions will be controlled simply by changing the applied magnetic field. The effects of disorder and interparticle interactions on the vortex configurations and vortex motion will be measured. Sincince such control over disorder and interactions is not possible in other disordered, interacting systems, the results of this research will provide valuable feedback for the theoretical understanding of these systems. Furthermore, the results of this research will deepen our understanding of vortex motion in high temperature superconductors. This a Research Planning Grant. ***
