Magnetic flux tuning of Fano-Kondo interplay in a parallel double quantum dot system

Abstract

We investigate the Fano-Kondo interplay in an Aharonov-Bohm ring with an embedded non-interacting quantum dot and a Coulomb interacting quantum dot. Using a slave-boson mean-field approximation we diagonalize the Hamiltonian via scattering matrix theory, and derive the conductance in the form of a Fano expression, which depends on the mean field parameters. We predict that in the Kondo regime the magnetic field leads to a gapped energy level spectrum due to hybridisation of the non-interacting QD state and the Kondo state, and can quantum-mechanically alter the electron's path preference. We demonstrate that an abrupt symmetry change in the Fano resonance, as seen experimentally, could be a consequence of an underlying Kondo channel.