Condensed-Matter Physics & Materials Science Seminar

Edge states of Quantum Hall systems offer a rich ground for testing
theoretical predictions on the properties of 1D strongly interacting
fermionic systems. More importantly they are considered clean realizations
the Luttinger Liquid description. In the past year we [1,2,3,4] have
examined a number of models that attempt to describe coupled edge density
waves in the quantum Hall regime in various different geometries and to
confront the large number of experimental observations that are at odds
with the models that have been thought to apply in the past. Work that is
currently in progress attempts to explain experimental results of the Pisa
experimental group in which tunneling through a constriction between
incompressible quantum Hall edge states is tuned from relevance to
irrelevance by adjusting a gate voltage. This property is explained in
terms of an interplay of the change in the connectivity of multi-mode edge
magnetosplasmon and the role played by the metallic gates on the structure
of the edge state, as well as the interactions between the edges. I will
talk also for unresolved questions that have appeared in recent
experiments in quantum Hall systems divided by thin
cleaved-edge-overgrowth barriers. An important difficulty that arises in
interpreting transport properties of QH line junction systems is the
uncertainty about the strength and sometimes even the sign of these
interactions, which can be difficult to estimate because of subtleties in
understanding their relationship to underlying Coulombic interactions,
because of edge reconstruction or because of the role played by the nearby
metallic gates. We propose theoretical ideas and experimental measurements
to obtain the required information. 1. E. Papa, et al , Phys.
Rev. Lett. 93, 126801 (2004) 2.Phys. Rev. B 72, 045324 (2005); Phys. Rev. B 72, 121304 (2005) 4. E. Papa, and T. Stroh, in
preparation