Optical study of quantum materials

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This proposal is for basic research on quantum materials with properties that cannot be explained with our current knowledge of physics and chemistry. If we understand how these materials work, we will be in a better position to take advantage of their strange and wonderful properties. Four projects are proposed. They all involve the uses infrared radiation as a probe. The first arises from our recent discovery of the breakdown of the widely accepted model for the frequency dependence of the electrical resistance in metals at low temperatures, the Landau Fermi liquid theory. We find that the theory fails in all cases where this dependence has been measured and want to test this further. Our work has been accepted by the high impact journal PNAS. The second project is a search for a new state of matter, the Dirac-Weyl semimetal. So far, no examples of this has been found but we have located a promising suspect: quasicrystals. They seem to have the properties needed: they are neither metals nor insulators but have strange in-between properties, an energy gap exactly at zero frequency, a property that results from topology. The third project involves our continued study of high temperature superconductivity using infrared, in novel materials. We will use our high magnetic field facility to look for the spin density wave state predicted to exist at high fields. The fourth project that ties the others together is an improvement of infrared techniques to keeps us on the forefront in the field. We will attempt to use infrared spectroscopy in pulsed ultra high magnetic fields. As an example of our past performance in this area, Sciencetech in London Ontario, founded by graduates from my group in part, manufactures an infrared spectrometer, the SPS-300, shipped to customers world wide. We designed it and my students wrote its original operating software. ESA used it to calibrate the Planck satellite that was launched to measure the microwave background radiation from the big bang.