This experimental research project is at the forefront of transport studies to clarify the unusual normal state properties of cuprates. The work focuses on anisotropy of electrical conduction in in-plane and out-of-plane directions, using extremely high quality and well-characterized single crystals of doped cuprates. The PI will measure the doping, temperature and magnetic field dependences of these conductivity anisotropies. The data will be analyzed for information about electronic structure and conduction mechanisms. Single crystals of YPrBa2Cu3O7 and TlSr2LuCaCu2Oy of variable dopings will be investigated. C-axis transport mechanisms will be investigated by comparing behavior in systems with and without chains. Evidence will be sought for a possible energy gap in the normal state spectrum of the CuO chains. Normal state conduction in strongly off-stoichiometry (under-doped and over-doped) cuprates will be probed by suppressing superconductivity with magnetic fields. Some of the work will be carried out at the NSF-supported National High Magnetic Field Laboratory in Tallahassee FL. This work is expected to advance fundamental understanding of the normal state conduction properties and electronic structure in the cuprates. More broadly, the results from this basic investigation may include fundamental new physical effects and also may provide insight into appropriate doping schemes to facilitate applications of cuprates for electronic sensors or devices. This highly interdisciplinary project strongly involves minority-group graduate students who pursue thesis research at both laboratory locations, and receive excellent training beneficial to a future career in industry, government or academia. %%% This experimental research project is concerns the unusual electrical properties and behavior of metallic oxides containing copper oxide planes. Some of these materials are high temperature superconductors, for example YBa2Cu3O7 which has a superconducting transition temperature of about 92 degrees on the Kelvin scale. The "normal state" properties of these conducting oxides at high temperatures or when the superconductivity is destroyed by an applied magnetic field, are the topics of this research. There are suggestions that these materials, even in the normal state, conduct electricity in ways that are very different from typical electrical conductors such as copper and silicon. Clarifiying these novel electrical behaviors may contribute to eventual applications of these materials in electronic devices such as magnetic field sensors or even computer logic devices. Some of the work will be carried out at the NSF-supported National High Magnetic Field Laboratory in Tallahassee FL. This highly interdisciplinary project strongly involves minority-group graduate students who pursue thesis research at both laboratory locations, and receive excellent training beneficial to a future career in industry, government or academia. ***
