Professor Dynes: Experimental Condensed Matter Physics
Growth of high Tc Superconductors: Aproject to grow high Tc thin films and characterize them is proposed. We have a laser ablation deposition system which is the method of choice for growing films of high Tc materials. The goal here is to grow various device structures which can be used as very sensitive SQUIDS (Superconducting Quantum Interference Devices). The physics and materials science of these materials will be studied in parallel with device investigations. Low temperature techniques, thin film processing including optical and e-beam lithography, and device physics will be applied.
The project consists of the design and construction of a pixel bioimaging detector system. The student will assist scientist and engineers in software development and electronic design of data acquisition and supporting hardware. Students who are interested in a combination of physics and engineering will be able to contribute well. Experience in C or C++ programming and electronics is desirable but these skills can be developed during the project.
Research on Luminous Infrared Galaxies and Quasars aims at understanding the physical nature of extremely luminous galaxies discovered with the Infrared Astronomical Satellite. These galaxies harbor quasar cores obscured by extreme amounts of dust. The project consists of data analysis of imaging and spectroscopic observations of Infrared Galaxies obtained at Lick, Palomar and Keck Observatories.
Single crystals of high temperature copper oxide superconductors will be prepared and characterized. Electrical resistivity and magnetic susceptibility measurements will then be performed in both the normal and superconducting states. Efforts will be made to increase the superconducting transition temperature as well as to optimize the superconduction properties of these single crystals.
As part of the Fermilab KTeV project UCSD is building a 3,100 channel highspeed, calorimeter based, trigger system. During the summer our group will work on:
Research into the chaotic dynamics of lasers. Experimental data is obtained in experiments at Georgia Tech. There exist good measurements and newanalysis tools for the study of this chaos. Models for these processes are based upon quantum mechanics. The models are adjusted based upon the experimental data and are analyzed using computers.
Research involves preparation and study of sub-micron, magnetic single domain particles, especially with respect to their magnetic and structural properties. They are interesting for several reasons. Firstly, they have reasonably high magnetizations and Curie temperatures, together with low structural symmetry. This combination should result in high coercive force and remanence. Secondly, they are very stable in air. Both these properties make them promising candidates for high density recording materials.
Investigation of the formation of mound structures in the aggregating slime mold Dictyostelium discoideum, one of the stages in this organism's developmental cycle. The work would be both experimental and computational. The experimental portion of the work would make use of cells which express green fluorescent protein. The fluorescence would enable the determination of the precise three dimensional shape. Computationally, the student would program a model of the organism which includes climbing motions and hence be able to predict mound shapes.
The project will consist of research on novel magnetic materials. The students will be involved in the preparation, characterization or measurements of these materials, using for example an ultra-high vacuum multi-source deposition system, various magnetometers for magnetic measurements, and a transport measurement apparatus.
Research in theoretical nuclear and particle astrophysics, especially the rates of the weak interaction of heavy nuclei in supernovas. These rates are important in understanding supernova heavy element nucleosynthesis. Deeper understanding of supernova nucleosynthesis may lead to new constraints on neutrino masses and putative neutrino dark matter. Much of the proposed work will involve use of a computer. Some familiarity with FORTRAN programming would be helpful, though not required (necessary skills can be picked up "on the fly").
Research involves developing methods for the preparation, characterization and study of the physical properties of one and zero dimensional, magnetic or superconducting structures. This requires the use of state of the art growth techniques together and the development of electron beam lithography methods for the preparation of the structures. The measurements consist of standard transport and magnetic measurements.
Another research project involves photoexcitation in high temperature superconductors, magnetotransport in magnetic multilayers and superlattices, search for new superconductors etc. All these are done using state of the art thinfilm growth equipment, structural characterization using a variety of insitu surface analysis techniques, ex-situ diffraction, and a number of physical properties measurements.
Research involves detector development for a detector to be used with a new particle accelerator (the "B-factory") under construction at the Stanford Linear Accelerator (SLAC). One research project involves a calibration scheme for the calorimeter for the detector. Neutrons from a deuterium beam "generator" will be used to activate a liquid, such as salt water, to make a short-lived source of high energy gamma rays which will be used to calibrate the big CsI crystal array in the detector. The project offers a choice of topics to work on: liquid transport problems, the measurement of the radiation spectrum of the activated liquid, the operating characteristics of the neutron generator and its radiation shielding problems, and computer simulation of how effective are the various schemes in making large numbers of gamma rays in as safe a manner as possible.