CAREER: Mesoscopic Physics of Disordered Superconductors: An Arena for Research and Education

9702661 Liu This experimental CAREER grant project focuses on the effects of disorder on meso-scale superconductors. A central research goal is to determine experimentally whether a negative local superfluid density exists. The experiments will make use of e-beam lithography and ultrathin film fabrication techniques and a well equipped low temperature measurement laboratory. Some specific aims are measurement of magnetoresistance and electric field effect in single and arrays of mesoscopic superconducting bismuth rings; measurement of mesoscopic fluctuations in magnetic fields in Auln alloy and Bi samples. The completion of these experiments will have a strong bearing on the question of the negative superfluid density. The proposed research will be integrated into an education plan to help enhance student learning and to train future scientists. The education plan is designed in part to promote women's participation in science, which will be beneficial for science and its well being as a profession. the fundamental knowledge which will be gained in this work will deepen our understanding of the fundamental nature of Cooper pairing correlation in disordered superconductors and may have significant impacts on several related fields. The behavior of mesoscopic scale superconductors is also relevant in potential applications including sensitive sensors of electromagnetic radiation and high performance low dissipation logic circuits. %%% This experimental CAREER grant project probes the fundamental changes in the phenomenon of superconductivity as the samples become very small or very thin, and as the superconducting material itself becomes disordered. The questions being studied are made more important and interesting by the essentially quantum mechanical nature of superconductivity. A focus of the work is to search for a particular theoretically possible eff ect, called a negative superfluid density. The existence of such as effect, if proven by work such as is proposed, would have implications for related areas of science. The long term outcome of such research could include the development of improved electronic devices for detecting electromagnetic radiation and/or for making rapid calculations. The education plan included in this project integrates research and education and aims to promote women's participation in science. ***