title: Duality between different geometries of a resonant level in a Luttinger liquid.
abstract: We prove an exact duality between the side-coupled and embedded geometries of a single level quantum dot attached to a quantum wire in a Luttinger liquid phase by a tunneling term and interactions. This is valid even in the presence of a finite bias voltage. Under this relation the Luttinger liquid parameter g goes into its inverse, and transmittance maps onto reflectance. We then demonstrate how this duality is revealed by the transport properties of the side-coupled case. Conductance is found to exhibit an antiresonance as a function of the level energy, whose width vanishes (enhancing transport) as a power law for low temperature and bias voltage whenever g > 1, and diverges (suppressing transport) for g < 1. On-resonance transmission is always destroyed, unless g is large enough.
authors.affiliation: The Minerva Center, Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel.
authors.forename: Moshe
authors.initials: M
authors.lastname: Goldstein
authors.forename: Richard
authors.initials: R
authors.lastname: Berkovits