This award will support collaborative research between Dr. Peter Yu, University of California at Berkeley, and Dr. Gerald Martinez, Service National des Champs Intenses, Grenoble, France. The objective of the project is to study the properties of semi- conductors and superconductors under high pressure. Pressure is a fundamental property of materials and can be utilized to alter the crystal structure of solids. In this project, the investigators will extend earlier work in using pressure to understand the properties of the DX center, which is a technological and scientifically interesting deep center in GaAs and GaA1As alloys. Pressure will be used to fabricate new semiconductor/metal and superconductor/superconductor superlattices. New techniques will be developed to measure magnetic susceptibility of samples under high pressure inside the diamond anvil cell. This collaboration will take advantage of the expertise at Berkeley in the areas of ab initio pseudopotential band structure calculations and in high pressure electrical and optical measure- ments. Complementing the Berkeley group are the unique high field magnet facilities in Grenoble. In addition, Dr. Martinez has access to novel SSL structures, such as short period GaAs/A1As superlattices grown in France.
