Unexpected Conductance Dip in Chains of Quantum Dots in the Kondo regime
Abstract
Using exactdiagonalization of small clusters and Dyson equation embedding techniques, the conductance of linear arrays of quantum dots is investigated [1]. The Hubbard interaction induces Kondo peaks at low temperatures for an odd number of dots N and a filling of one particle per dot. Remarkably, for N=3,5,... the Kondo peak is split in half by a deep minimum, and the conductance vanishes at the gate voltage that induces particlehole symmetry. Tentative explanations for this unusual effect are proposed, including an interference process between two channels contributing to G, with one more and one less particle than the exactlysolved cluster groundstate. The Hubbard interaction and fermionic statistics of electrons also appear to be important to understand this phenomenon. Although most of the calculations used a particlehole symmetric Hamiltonian and formalism, results also presented here showing that the conductance dip exists even when this symmetry is broken. [1] C.A. Büsser, Adriana Moreo and Elbio Dagotto, condmat/0308413
 Publication:

APS March Meeting Abstracts
 Pub Date:
 March 2004
 Bibcode:
 2004APS..MARP11007B