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. The 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.

Published version

References in corpus (5)

• The numerical renormalization group method for quantum impurity systems
• Phase transitions in the pseudogap Anderson and Kondo models: Critical dimensions, renormalization group, and local-moment criticality
• Magnetic field dependent transmission phase of a double dot system in a quantum ring
• Kondo Effect in a Many-Electron Quantum Ring
• Finite-temperature conductance signatures of quantum criticality in double quantum dots