Multiple Fano resonance in a two-dot system

Interference effects in electron transport across a double quantum dot are studied theoretically within the framework of the Hartree–Fock approach by means of the Green function formalism based on the equation of motion method. An influence of inter–dot Coulomb repulsion of strength U on conductance spectra is analyzed and a limit of U comparable to the tunneling rate between two dots is discussed in detail. A variety of Fano features, including multiple (double or triple) Fano resonances, is found as a result of interferences between four states, molecular bonding and antibonding ones, as well as these states shifted by U. The number and intensity of Fano resonance peaks present in the conductance spectrum strongly depend on the relation between parameters which describe the inter-dot tunneling rate and inter-dot Coulomb interaction between electrons.