The fractional quantum Hall fluids are some of the most nontrivial strongly correlated states of matter. Existing theories of the fractional quantum Hall effect relies on the notion of the composite fermion. A long-standing problem of existing theories of the composite fermion is the lack of particle-hole symmetry of the lowest Landau level. I will describe how the particle-hole symmetry took a central role in recent theoretical discussions of the fractional quantum Hall effect; in particular, how a recent synthesis, motivated by the physics of graphene and topological insulators, has led to a new understanding of the low-energy quasiparticle of the half-filled Landau level. According to the new picture, the composite fermion is a Dirac particle with a nontrivial pi Berry phase around the Fermi surface. Distinctive consequences of the new proposal are outlined.
Held Tuesdays at 4:30 pm in the William R. Hewlett Teaching Center, room 201.
Refreshments in the lobby of Varian Physics at 4:15 pm.
Spring 2015/2016, Committee: M. Schleier-Smith (Chair), G. Gratta, B. Lev, S. Zhang