Coherent Transport through Systems of Coupled Quantum Dots

P. Trocha a and J. Barnaś a,b a Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań, Poland b Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland

Full Text PDF

Received: 9 06 2007;

Spin-dependent electronic transport through two coupled single-level quantum dots attached to ferromagnetic leads with parallel and antiparallel magnetizations is analyzed theoretically. The intra-dot Coulomb correlation is taken into account, while the inter-dot Coulomb repulsion is omitted. Conductance and tunnel magnetoresistance associated with magnetization rotation are calculated by the nonequilibrium Green function technique. The relevant Green functions are derived by the equation of motion method in the Hartree-Fock approximation. The dot occupation numbers and the Green functions are calculated self-consistently. The interference effects in electronic transport through quantum dots are analyzed in two different configurations. It is shown that the Fano resonance in conductance can be observed even for vanishing inter-dot hopping parameter t. The interplay of the interference effects and the Coulomb interactions in quantum dots is also analyzed.

DOI: 10.12693/APhysPolA.112.473 PACS numbers: 73.23.-b, 73.21.La, 73.23.Hk