9501160 Adams Experiments are proposed to study the transport properties of two very different disordered two-dimensional systems. The first area of study is the superconductor-insulator (S-I) transition in granular aluminum films by the application of a parallel magnetic field to drive the transition. This technique, which avoids complications associated with flux flow resistance, has proven to be very useful in determining the relative roles of disorder, Josephson coupling, and Coulomb blockade in the generic characteristics of granular film S-I transitions. These studies are ultimately aimed at developing a superconducting field- effect transistor in a granular system. In addition, studies of the effects of disorder and electron-electron interactions in the transport properties of electrons sprayed onto solid hydrogen are being made. This is a model system from which one can obtain valuable insights into the transport properties of more conventional disordered semiconducting systems. %%% Experiments are proposed to study the electrical properties of two very different disordered two-dimensional types of material. The first area of study concerns the mechanisms involved in the destruction of superconductivity in very thin aluminum films. This work will attempt to determine the relative roles of disorder, superconductivity, and single electron charging effects in the generic electrical characteristics of granular aluminum films at low temperatures. The ultimate goal of these studies is the development of a superconducting field-effect transistor using granular materials. In addition, studies of the effects of disorder and electron-electron interactions in the electric transport properties of electrons sprayed onto solid hydrogen are being made. This material serves as a model from which one can obtain valuable insights into the transport properties of more conventional semic onducting materials, such as those used in the microelectronics industry. ***
