A Talk on Landau Levels in a 2-D Electron Gas
A talk scheduled by the Physics Department, LUMS the titled Landau Levels in a 2-D Electron Gas with an Arbitrary Potential
Date: Wednesday, September 5, 2012
Time: 03:30 p.m. to 4:30 p.m.
Venue: SSE Block, 1st floor, Smart Lab, Computer Science Department
Speaker: Dr. Pervez Hoodbhoy, Professor, Physics Department, LUMS
Abstract: We re-examine the behaviour of a 2-dimensional electron gas that is subject to both a large perpendicular magnetic field as well as spatially varying internal electric fields. Of the two guiding centre coordinates, we choose one to be diagonal. This makes the energy a local function of position, allowing for an easy visualisation of the transverse and longitudinal responses to externally imposed fields, as well as the spatial distribution of the (transverse) Hall current inside the sample. It turns out that the transverse current is not, as is usually asserted, entirely at the sample's edges. The Laughlin-Halperin trick is implemented and shown to lead to a topological phase that ensures the quantisation of transverse conductivity.