Thermal dependence of the zero-bias conductance through a nanostructure

We show that the conductance of a quantum wire side-coupled to a quantum dot, with a gate potential favoring the formation of a dot magnetic moment, is a universal function of the temperature. Universality prevails even if the currents through the dot and the wire interfere. We apply this result to the experimental data of Sato et al.[Phys. Rev. Lett. 95, 066801 (2005)].Comment: 6 pages, 3 figures. More detailed presentation, and updated references. Final version

Susceptibility of a two-level atom near an isotropic photonic band edge: transparency and band edge profile reconstruction

We discuss the necessary conditions for a two-level system in the presence of an isotropic band edge to be transparent to a probe laser field. The two-level atom is transparent whenever it is coupled to a reservoir constituted of two parts - a flat and a non-flat density of modes representing a PBG structure. A proposal on the reconstruction of the band edge profile from the experimentally measured susceptibility is also presented.Comment: 15 pages, 3 figure