Acquisition of Optical Access Superconducting Magnet System for Materials Physics Research and Education

Suny At Buffalo, Amherst NY

Investigators

Abstract

0076466 Markelz This grant supports the acquisition and use of a versatile, optical-access, high-field (10T), split-coil superconducting magnet system for experimental investigations of quantum dots and quasi-two-dimensional excitons in semiconductors, and the dynamical conductivity of high Tc superconductors. This research is directed at achieving an understanding of several outstanding physics problems: 1) Internal transitions of excitons in lateral fluctuation quantum dots in GaAs/AlGaAs, 2) dynamics of photoexcited neutral excitons in GaAs/AlGaAs quantum wells, and 3) the dynamical conductivity and relaxation times in high temperature superconductors (HTSC) in the mid-infrared and terahertz regions of the spectrum. An improved understanding of the behavior of the fundamental optical excitation of low-dimensional semiconductor structures, the exciton, which may be important in implementations of quantum computation, is also expected to be developed from these studies. In addition, this research will provide insight into one of the fundamental conundrums of high temperature superconductor materials, the apparent non-Fermi liquid transport behavior in the normal state. This project supports the acquisition of a high magnetic field, optical access, cryogenic system to enable unique optical studies of materials systems of fundamental and technological interest using our existing versatile optical systems that range in frequency from the microwave to the ultra violet. We will initially focus on two materials systems: quantum confined electronic structures in semiconductors and high temperature superconductors. This research is directed at achieving an understanding of several outstanding physics problems: 1) Internal transitions of excitons in quantum dots in GaAs/AlGaAs, 2) dynamics of photoexcited neutral excitons in GaAs/AlGaAs quantum wells, and 3) the dynamical conductivity and relaxation times in high temperature superconductors (HTSC) in the mid-infrared and terahertz regions of the spectrum. These studies will improve present day understanding of the behavior the fundamental optical excitations of low-dimensional semiconductor structures, which may be important in implementations of quantum computation. In addition, this research will provide insight into the origins of high temperature superconductivity.