From quantized anomalous Hall effect to interface enhanced high temperature superconductivity

Event Date: 

Friday, February 28, 2014 - 11:30am

Event Location: 

  • Elings Hall 1601

Event Contact: 

Speaker:

Professor Qi-Kun Xue Department of Physics, Tsinghua University Beijing, China

Abstract:

Molecular beam epitaxy (MBE) is a powerful technique for preparation of semiconductors and related heterostructures, among which extremely high mobility two dimensional electron gas and multiple quantum well structure for cascade laser are two of the well-known examples. Combining MBE with scanning tunnelling microscopy (STM) and angle resolved photoemission spectroscopy (ARPES) can even push its power to an unprecedented level for condensed matter physics. In this talk, I would present our MBE-STM-ARPES study of topological insulators and iron-based superconductors that have recently attracted extensive attention. I would first show how we can realize the quantized anomalous Hall effect by atomic-level control of band-engineered and magnetically doped topological insulators with MBE-STM-ARPES with great advices from theoreticians. I then show the advantage of such combination by the interface enhanced high temperature superconductivity in single unit-cell FeSe films on SrTiO3. Implications on exploring other exotic quantum phenomena such as Majorana fermions and magnetic monopole in topological insulators and high Tc superconductors as well as their heterostructures will also be discussed.