Abstract:
Three-dimensional (3D) topological insulators (TIs) represent a new state of quantum matter with a bulk gap generated by the spin-orbit interaction and an odd number of relativistic Dirac fermions on the surface. The unusual surface states of TIs can be the host for many striking quantum phenomena, such as an image magnetic monopole induced by an electric charge and Majorana fermions induced by the proximity effect from a superconductor. Since the initial theoretical proposals, several families of TIs have been experimentally confirmed.
In this talk, I will report our recent progress on the investigation of thin film TIs with angle-resolved photoemission spectroscopy (ARPES). We were able to directly visualize their non-trivial electronic structures on ex-situ grown TI thin films, which have shown great promise for electronic and optical applications.

Biosketch:
Dr. Yulin Chen received his B.S. degree in physics from USTC in 2000, and obtained his Ph.D. in physics at Stanford University in 2008, working with Prof. Zhi-xun Shen. After working as a postdoc (2008-2009), an associate staff scientist (2009-2010), and a staff scientist (2010-2011) at SLAC National Accelerator Laboratory, he joined the Department of Physics at Oxford University in 2012, as a University Lecturer & Fellow of Jesus College. He is a recipient of Outstanding Young Researcher Award (Macronix Prize) from the International Organization of Chinese Physicists and Astronomers (2012) and a William E. and Diane M. Spicer Young Investigator Award from Stanford Synchrotron Radiation Lightsource (2009). His research interests lie in experimental condensed matter physics; and specifically, in understanding the behavior of electrons in unconventional materials, such as topological quantum matters and strongly correlated systems.