Conductance anomalies in quantum wires
  We study the conductance threshold of clean nearly straight quantum wires in the magnetic field. As a quantitative example we solve exactly the scattering problem for two-electrons in a wire with planar geometry and a weak bulge. From the scattering matrix we determine conductance via the Landauer-Buettiker formalism. The conductance anomalies found near 0.25(2e^2/h) and 0.75(2e^2/h) are related to a singlet resonance and a triplet resonance, respectively, and survive to temperatures of a few degrees. With increasing in-plane magnetic field the conductance exhibits a plateau at e^2/h, consistent with recent experiments. 
T. Rejec (J. Stefan Institute, Ljubljana, Slovenia), A. Ramsak   (Faculty of Mathematics and Physics, J. Stefan Institute, L...