Physics Colloquium - Probing Dirac Electron Physics in Graphitic Materials

Event Date: 

Tuesday, March 1, 2016 - 4:00pm

Event Location: 

  • Broida 1640

Speaker:

Feng Wang

Department of Physics, UC Berkeley

 

Abstract:

Electrons in monolayer graphene are described by massless Dirac electrons, which exhibit unique quantum phenomena due to the pseudospin and Berry phase of the massless electrons. In this talk, I will discuss our effort in probing massive Dirac electrons in gapped bilayer graphene, which can be described by a quantum valley Hall insulator with non-trivial Chern number for individual valleys. We show that a tunable bandgap up to 200meV can be induced in bilayer graphene with electrical gating.

In addition, we observe a topologically protected 1D conducting channel at the domain boundary of AB-BA bilyaers, which can be attributed to the quantum valley Hall edge states in gapped bilayer graphene. I will also discuss one-dimensional plasmon arising from Luttinger liquid of Dirac electrons in metallic carbon nanotubes, which exhibit semi-quantized propagation speed and remarkable sub-wavelength plasmon confinement.