ECE Colloquium - April 30, 2014
Dr. Seongshik Oh, Rutgers, Department of Physics & Astronomy
CoRE Building Lecture Hall
Title: Atomic-layer-by-layer molecular beam epitaxy for topological insulators and artificial functional oxides
Molecular beam epitaxy (MBE), which was invented in late 1960s in Bell lab and advanced over the past decades, allows growth of various thin film structures with atomic precision. In particular, it led to a number of major breakthroughs in semiconductor systems such as fractional quantum Hall effect, high electron mobility transistor (HEMT) and quantum cascade lasers. In our lab, we are applying this MBE technology beyond the conventional semiconductors to investigate novel materials such as topological insulators and artificial functional oxides that are either difficult or impossible to grow using other methods. Topological insulators (TI) are a new class of materials that were discovered several years ago and are being heavily investigated, yet mostly in the physics community. One of the most intriguing properties of TIs is that they are supposed to have highly mobile metallic surface states while inside of the material is insulating. However, real TIs suffer from serious material problems that make the utilization of these surface states nearly impossible. In this talk, I will overview the MBE technology and how it can be used to study topological insulators and functional oxides. Then, I will discuss how we utilize this technique to overcome the material problems of TIs and implement various novel TI platforms.
Seongshik Oh received his Ph.D. in Physics from University of Illinois, Urbana-Champaign in 2003 and was a postdoctoral researcher at National Institute of Standards and Technology, Boulder between 2004 and 2007. In 2007 he joined the faculty of Department of Physics and Astronomy at Rutgers University, where he is currently an Associate Professor. His research interests are in synthesis and electronic properties of two dimensional quantum materials and devices. He received the NSF CAREER award and published over 50 journal articles and book chapters. More details can be found in his group website: mbe.rutgers.edu