Christopher Bell (SIMES Friday Seminar)

Date(s) - Feb 8 2013
11:00 AM - 12:30 PM

Shasta Room, Bldg. 40, Room 361


Superconductivity & magnetism: Surprises and opportunities in thin film oxide heterostructures

Thin film heterostructures are ubiquitous in both research and modern electronic applications. They allow us to address fundamental questions such as the limits of long range ordering in reduced dimensions, force competing orders together on the nanoscale to study their interactions, and create completely new emergent states of matter and devices. Such heterostructures in transition metal oxides are of particular interest, due to the many novel groundstates that can be generated in the bulk, and hence combined in high quality crystalline films. In many of these materials the carrier densities in the bulk are in a semiconducting regime which makes them highly tunable, and suitable for use in architectures borrowed from conventional silicon technologies. Even for much more metallic materials, as we approach the ultrathin regime their properties become highly sensitive to local perturbations: new ordering can emerge, and be controlled in a precise manner.
In this presentation I will introduce how we make our thin films, and then discuss several examples of new physics in oxide hetereostructures, including the formation of self-assembled mesoscopic spin-valves in ultrathin manganites, and high-mobility two-dimensional superconductivity in doped SrTiO3. Finally I will present some ideas concerning the opportunities that can arise with the utilization of the ultrafast probes available at SLAC to study dynamic effects in these systems, in particular focusing on coupled superconductor / ferromagnet hybrid systems.