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Anomalies in the conduction edge of quantum wires

T. Rejec·A. Ramsak·J. H. Jefferson
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Abstract

We study the conductance threshold of clean nearly straight quantum wires in which an electron is bound. We show that such a system exhibits spin-dependent conductance structures on the rising edge to the first conductance plateau, one near 0.25(2e^2/h), related to a singlet resonance, and one near 0.75(2e^2/h), related to a triplet resonance. As a quantitative example we solve exactly the scattering problem for two-electrons in a wire with circular cross-section and a weak bulge. From the scattering matrix we determine conductance via the Landauer-Buettiker formalism. The conductance anomalies are robust and survive to temperatures of a few degrees. With increasing magnetic field the conductance exhibits a plateau at e^2/h, consistent with recent experiments.

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T. Rejec, A. Ramsak, J. H. Jefferson. 2000-07-26. Anomalies in the conduction edge of quantum wires. https://arxiv.org/abs/cond-mat/0007419

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