title: Numerical renormalization group at marginal spectral density: application to tunneling in Luttinger liquids.
abstract: Many quantum mechanical problems (such as dissipative phase fluctuations in metallic and superconducting nanocircuits or impurity scattering in Luttinger liquids) involve a continuum of bosonic modes with a marginal spectral density diverging as the inverse of energy. We construct a numerical renormalization group in this singular case, with a manageable violation of scale separation at high energy, capturing reliably the low energy physics. The method is demonstrated by a nonperturbative solution over several energy decades for the dynamical conductance of a Luttinger liquid with a single static defect.
authors.affiliation: Institut Néel, CNRS and Université Joseph Fourier, Grenoble, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Freyn
authors.forename: Serge
authors.initials: S
authors.lastname: Florens