Spin-dependent resonances in the conduction edge of quantum wires

The conductance through a quantum wire of cylindrical cross section and a w eak bulge is determined exactly for two electrons within the Landauer-Butti ker formalism. We show that this "open" quantum dot exhibits spin-dependent resonances resulting in two anomalous structure on the rising edge to the first conductance plateau, one near 0.25(2e(2)/h), related to a singlet res onance, and one near 0.7(2e(2)/h), related to a triplet resonance. These re sonances are generic and robust, occurring for other types of quantum wires and surviving to temperatures of a few degrees.