Quantum Hall systems were the first discovered examples of Topological Insulators. They have a gap to charged excitations in the bulk, but possess gapless modes at the edges. These gapless modes are chiral, which means they travel only in one direction at a given edge, are robust against disorder, and are responsible for all the transport properties of quantum Hall states. The nature of the bulk constrains the number and chiralities of the edge modes. However, within these constraints, phase transitions called edge reconstructions can occur to minimize the electrostatic energy as the potential that confines the electrons to the sample is varied. I will describe a new class of edge reconstructions which are primarily driven by exchange rather than electrostatics, and are expected to occur generically for partially polarized quantum Hall states. I will also discuss some very striking experimental signatures expected of such reconstructed edges.
Spin-Mode-Switching at Integer Quantum Hall Edges
Date:
-
Location:
CP 155
Speaker(s) / Presenter(s):
Ganpanthy Murthy (University of Kentucky)
Event Series: