We report on an investigation of the Kondo effect induced by an interdot off-site interaction in a double-quantum-dot system. In the limit of zero interdot tunnel coupling ${(t}_C=0),$ we discuss a cotunneling process involving the exchange of electron positions between the two quantum dots. At low temperatures this process induces a Kondo resonance with a peculiar characteristic: the Kondo resonance of one dot is pinned at the chemical potential of the lead that is attached to the other dot. When coupling $t_C\ne 0,$ cotunneling processes involving molecular states which span the two dots induce several Kondo resonances in each dot. Then the conductance of the double-dot device shows sharp features including multiple peaks and abrupt drops having typical Kondo character. We discuss the physical origin of these features.

• Received 27 March 2002

DOI:https://doi.org/10.1103/PhysRevB.66.155308