AVS 58th Annual International Symposium and Exhibition
    Magnetic Interfaces and Nanostructures Division Wednesday Sessions
       Session MI-WeA

Invited Paper MI-WeA1
Novel Properties of Topological Insulator Thin Films Prepared by Molecular Beam Epitaxy

Wednesday, November 2, 2011, 2:00 pm, Room 105

Session: Spintronics, Magnetoelectronics, Multiferroics, and Dilute Magnetic Semiconductor Applications
Presenter: Qi-Kun Xue, Tsinghua University, China
Correspondent: Click to Email
We have grown topological insulator thin films of Bi2Te3, Bi2Se3 and their alloys on Si(111), 6H-SiC(0001) and sapphire substrates by using state-of-art molecular beam epitaxy (MBE). We studied nontrivial surface states and their thickness-dependence of the films by in situ angle resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy/spectroscopy (STM/STS). By direct imaging standing waves associated with magnetic and nonmagnetic impurities and steps on Bi2Te3 and Bi2Se3 (111) surfaces, we show that the topological states have a surface nature and are protected by the time reversal symmetry. We demonstrated the high mobility of the Bi2Se3 films by direct observation of Landau quantization. We also studied the growth of superconducting and magnetic thin films on the topological insulator films. Implication on probing Majorana fermions and topological magneto-electric effect will be discussed.