Date: Tuesday, September 30, 2014
Time: 11:00 am
Speaker: Susanne Stemmer, UC Santa Barbara
Title: Structure and Properties of Oxide Heterostructures
Location: 67-3111 Chemla Room
This talk will focus on recent research activities in our group in the areas of advanced structural characterization, growth, and properties of oxide thin films and heterostructures. In the first part of this presentation we discuss recent progress in developing quantitative scanning transmission electron microscopy (STEM) techniques. We discuss examples where such techniques have led to unique insights, such as measurements of small structural distortions with unit cell spatial resolution and the 3D imaging of individual dopant atoms. In the second part we will focus on the properties of two-dimensional electron gases at oxide interfaces grown by molecular beam epitaxy, which exhibit unique properties, such as strong electron correlations, superconductivity and magnetism. We will discuss an example for such an interface, between strongly correlated Mott insulating rare earth titanates and the band insulator SrTiO3. We report on electron correlation effects, such as magnetism, mass enhancement and non-Fermi liquid behavior, in extremely high carrier density SrTiO3 quantum wells that can be obtained using these interfaces. We discuss the role of the quantum well symmetry in these properties.
The work was performed in collaboration with Jinwoo Hwang, Jack Zhang, Clayton Jackson, Santosh Raghavan, Pouya Moetakef, Evgeny Mikheev, and Leon Balents.