This experimental research is on the infrared and microwave magneto-optical properties of Type II superconductors, with emphasis on cuprates, in both normal and superconducting states. Measurements of magneto-transmission of superconducting films using circularly polarized radiation with frequency and temperature variation, followed by kramers-Kronig analysis will determine the full complex frequency-dependent magneto- conductivity tensor. Features in such data recently discovered to be related to vortex pinning; the hybridized vortex pinning/cyclotron resonance, the hybridized vortex pinning/vortex core resonance, and the low frequency depinning loss band, will be a focus of the experimental work. The effects on these properties of vortex pinning as introduced by ion implantation will be studied. Additional topics include studies of Josephson plasmons, and of plasma and magneto-plasma modes of arrays of superconducting disks. These studies are novel and will provide new information on high temperature superconductivity, with the possibility of opening new paths for the science and technology of superconductivity. %%% This experimental research project makes use of sophisticated optical measurements to clarify the interaction of magnetic fields with cuprate (high Tc) superconductors. These superconductors have the potential for application in motors and generators, where the loss-free electrical conduction and potentially high levels of magnetic field could lead to smaller, lighter, and more efficient motors and generators. The full exploitation of this potential has not been reached thus far, because of heat generating motions of the magnetic field lines inside the cuprate material. Such motions, and how they may be reduced by introduction of "pinning cent ers" by irradiation or other means, are one of the topics to be clarified. This experimental grant may thereby help to develop an improved electrical technology. Results from this research may include unusual new effects or structures which may find application in technology. This research project is interdisciplinary in nature and involves graduate students who will be excellently trained to enter positions in industry, government or education. *** This experimental research is on the infrared and microwave magneto-optical properties of Type II superconductors, with emphasis on cuprates, in both normal and superconducting states. Measurements of magneto-transmission of superconducting films using circularly polarized radiation with frequency and temperature variation, followed by Kramers-Kronig analysis will determine the full complex frequency-dependent magneto- conductivity tensor. Features in such data recently discovered to be related to vortex pinning; the hybridized vortex pinning/cyclotron resonance, the hybridized vortex pinning/vortex core resonance, and the low frequency depinning loss band, will be a focus of the experimental work. The effects on these properties of vortex pinning as introduced by ion implantation will be studied. Additional topics include studies of Josephson plasmons, and of plasma and magneto-plasma modes of arrays of superconducting disks. These studies are novel and will provide new information on high temperature su perconductivity, with the possibility of opening new paths for the science and technology of superconductivity. %%% This experimental research project makes use of sophisticated optical measurements to clarify the interaction of magnetic fields with cuprate (high Tc) superconductors. These superconductors have the potential for application in motors and generators, where the loss-free electrical conduction and potentially high levels of magnetic field could lead to smaller, lighter, and more efficient motors and generators. The full exploitation of this potential has not been reached thus far, because of heat generating motions of the magnetic field lines inside the cuprate material. Such motions, and how they may be reduced by introduction of "pinning centers" by irrradiation or other means, are one of the topics to be clarified. This experimental grant may thereby help to develop an improved electrical technology. Results from this research may include unusual new effects or structures which may find application in technology. This research project is interdisciplinary in nature and involves graduate students who will be excellently trained to enter positions in industry, government or education. ***
