Seminar on Disorder and strong electron correlations: "Multi-component fractional quantum Hall effect in graphene"
Starts 24 Feb 2011 11:30
Ends 24 Feb 2011 20:00
Central European Time
Leonardo da Vinci Building Luigi Stasi Seminar Room
Strada Costiera, 11
I - 34151 Trieste (Italy)
A milestone in graphene research was the 2005 discovery of an integer quantum Hall effect in this novel carbon-based two-dimensional (2D) electron system. Contrary to its manifestation in conventional 2D electron systems, such as in semiconductor heterostructures, the graphene quantum Hall effect reflects the "ultra-relativistic" character of the underlying carriers, via a particular sequence of plateaus in the transverse Hall resistance.
A natural question arises from this discovery: what about the fractional quantum Hall effect in graphene? Does it also reflect the ultra-relativistic character of the charge carriers? To what extent is it different from the fractional quantum Hall effect in (non-relativistic) semiconductor heterostructures? Many of these questions remain open from an experimental point of view, although some fractional states have recently been observed in the two- and four-terminal configuration.
This talk aims at a theoretical perspective on the fractional quantum Hall effect in graphene, namely in view of its multi-component character due to the fourfold spin-valley degeneracy, which is approximately respected by the underlying electron-electron interactions. This theoretical perspective will be confronted with recent experimental advances.