English

Do quantum dots allow one access to pseudogap Kondo physics?

Mesoscale and Nanoscale Physics 2009-11-10 v1 Strongly Correlated Electrons

Abstract

For the last decade, tunable quantum dot systems have allowed the investigation of Kondo physics wherein the quenching of a single spin on an artificial atom affects the conductance. The pseudogap Kondo model featuring a density of states ρ(ϵ)\rho(\epsilon) = Cϵr|\epsilon|^{r}, introduced by Withoff and Fradkin in 1990 was predicted to exhibit Kondo-like physics above a critical value of the Kondo coupling, Jc_c, which several groups have shown by numerical renormalization group (RG) is finite for r<1/2< {1/2}. Gonzalez-Buxton {\it{et al}} showed that the strong coupling limit of the particle-hole symmetric model leads to a non-trivial π(1r)2\frac{\pi (1-r)}{2} phase shift at low temperatures indicating incomplete screening of the local moment, while away from particle-hole symmetry one generically flows towards a ground state with δπ\delta \sim \pi. We examine the implications of this model for quantum dots whose leads are Fermi-liquid-like, yet possess a tunneling density of states which is suppressed at the Fermi energy as a power law.

Keywords

Cite

@article{arxiv.cond-mat/0407583,
  title  = {Do quantum dots allow one access to pseudogap Kondo physics?},
  author = {John Hopkinson and Karyn Le Hur and Emilie Dupont},
  journal= {arXiv preprint arXiv:cond-mat/0407583},
  year   = {2009}
}

Comments

2 pages, 1 figure, poster to be presented at SCES'04 Karlsruhe July 26-30