Condensed Matter Seminar Series
Conductance of a quantum wire in the Wigner crystal regime
Argonne National Lab & Duke University
Thursday September 18, 1h30 pm, Room 234, Physics Building
Host: Denis Ullmo
Abstract: This talk addresses the effect of Coulomb interactions on the
conductance of a single-mode quantum wire connecting two bulk leads.
When the density of electrons in the wire is very low, they arrange in
a finite-length Wigner crystal. In this regime the electron spins form
an antiferromagnetic Heisenberg chain with exponentially small coupling
J. An electric current in the wire perturbs the spin chain and gives
rise to a temperature-dependent contribution of the spin subsystem to
the resistance. At low temperature T << J this effect is small, and
the conductance of the wire remains close to 2e^2/h. At T >> J the
spin effect reduces the conductance to e^2/h.