This individual investigator award will support continued infrared magneto-transport studies of cuprate high temperature superconductors in order to elucidate the anomalous transport observed in these materials. The emphasis will be on the pseudogap state of the underdoped cuprates. Measurements of the infrared Hall effect in thin single crystal samples will be made over the frequency range corresponding to the important interaction energies. These measurements will use the highly sensitive polarization modulation technique developed by the PI. The magneto-transport data will be critically compared with the data from Angular Resolved Photoemission experiments on the same materials. In the superconducting state the goal is to provide the phenomenology that will allow an understanding of vortex dynamics in high Tc superconductors both below and possibly above Tc in the pseudogap state. The proposed studies will break new ground in superconductivity research and they hold the promise of opening new paths for the science and technology of superconductors. The broader impact of this program includes the development of novel measurement techniques for materials science and the training of high school students, undergraduate science majors, graduate students and post docs in infrared materials physics.
Magneto-optical measurements of metals with strongly interacting electrons, mostly the cuprate high temperature superconductors, will be performed at infrared frequencies. The measurements will be made in high magnetic fields and at cryogenic temperatures. The proposed studies probe the electrical transport properties of the cuprates, which appear highly anomalous in comparison with conventional metals and superconductors. The measurements cover the frequency range corresponding to the important interaction energies of the electrons. The results may provide important new insights into the mechanisms of high temperature superconductivity and in the understanding of materials with strongly interacting electrons in general. They also hold the promise of opening new paths for the science and technology of these novel materials. The techniques developed in this program are novel and may be used in other laboratories. The project also involves the training of undergraduate students, graduate students and post docs in materials physics. In addition, new teaching demonstrations of materials science in magnetic fields will be developed.
