title: Tunable pseudogap Kondo effect and quantum phase transitions in Aharonov-Bohm interferometers.
abstract: We study two quantum dots embedded in the arms of an Aharonov-Bohm ring threaded by a magnetic flux. This system can be described by an effective one-impurity Anderson model with an energy- and flux-dependent density of states. For specific values of the flux, this density of states vanishes at the Fermi energy, yielding a controlled realization of the pseudogap Kondo effect. The conductance and transmission phase shifts reflect a nontrivial interplay between wave interference and interactions, providing clear signatures of quantum phase transitions between Kondo and non-Kondo ground states.
authors.affiliation: Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. diasdasilval@ornl.gov
authors.forename: Luis G G V
authors.initials: LG
authors.lastname: Dias da Silva
authors.forename: Nancy
authors.initials: N
authors.lastname: Sandler
authors.forename: Pascal
authors.initials: P
authors.lastname: Simon
authors.forename: Kevin
authors.initials: K
authors.lastname: Ingersent
authors.forename: Sergio E
authors.initials: SE
authors.lastname: Ulloa