Thursday, October 25, 2012
East Bridge 201
Physics Research Conference
Topological Insulators: Opportunities, Materials and Challenges
Kang L. Wang, UCLA
Quantum Anomalous Hall One critical challenge of today's silicon integrated circuits electronics is the power dissipation. Three-dimensional (3D) topological insulators (TIs) have attracted great attention from both the theoretical and technology aspects -- dissipation-less electron transport which may enable low dissipation devices and technology and axion electrodynamics, which would enable electric field control of magnetism and open entirely new electromagnetism applications. However, the observation of surface carrier transport and axion electrodynamics is hindered by the dominant bulk carrier conduction. I will describe the present progress and challenges of materials growth of Bi2Se3, Bi2Te3 and their related materials on different substrates by molecular beam epitaxy (MBE). Doping control to realize the pn junction is also realized for potential device applications. I will also discuss the use of magnetic doping to realize the control of conductivity and the opening of the energy gap of the metallic surface states as a pathway to observe quantum anomalous Hall and the demonstration of axion electrodynamics. The results show that topological insulator devices using the Dirac Fermions of the metallic surface states may be realized for low dissipation devices and other new electromagnetics applications.