19th November 2020
The electronic properties of complex-oxide heterostructures and nanostructures exhibit a variety of emergent quantum phases that are highly unusual. The underlying material system resembles a semiconductor heterostructure, except the materials are perovskite insulators LaAlO3 and SrTiO3. The conductive properties at interfaces formed from these two materials exhibit rich behavior, including magnetism and superconductivity. The conductivity at the interface can be reversibly controlled at extreme nanoscale dimensions using a conductive atomic force microscope. The resulting nanostructures (e.g., electron waveguides) exhibit surprising behavior not found in other materials.
I will focus on one class of behavior, the ballistic transport of electrons, electron pairs, and quantum liquids formed from larger bound states as well (trions, quaternions, etc). The signatures of these phases are observed at low temperatures and high magnetic fields. The experiments described here benefit from two major systems: Asylum Research (Oxford Instruments) atomic force microscopes which have been customized for conductive lithography, and a wet cryostat capable of achieving 20 T magnetic fields.
Date: Wednesday 19th Novmeber
Time: 11am ET / 4pm GMT
Dr. Jeremy Levy is a Distinguished Professor of Condensed Matter Physics at the University of Pittsburgh in the Department of Physics and Astronomy and Founding Director of the Pittsburgh Quantum Institute (http://pqi.org). He received an A.B. degree in physics from Harvard University in 1988, and a Ph.D. degree in physics from UC Santa Barbara in 1993. After a postdoctoral position at UC Santa Barbara, he joined the University of Pittsburgh in 1996. His research interests center around the emerging field of oxide nanoelectronics, experimental and theoretical realizations for quantum computation, semiconductor, and oxide spintronics, quantum transport, and nanoscale optics, and dynamical phenomena in oxide materials and films.