Phase transition in small metallic junctions with quasiparticle dissipation

We report Monte Carlo simulations for the T=0 phase diagram of a mesoscopic metallic junction. We present some evidences as a T=0 phase transition induced by the dispersion strength {α}. In the strong-coupling region the predictions of the spin-wave theory turn out to be correct and the algebraic decay of correlations implies quasi-long-range order, corresponding to the absence of a Coulomb-blockade voltage threshold. The critical junction resistance is estimated to be Rₜ{}0.6 k{Ω}.