Interplay between quantum interference and electron interactions in a Rashba system.

We investigate theoretically a nanoscopic device in which quantum interference of electron waves takes place in the presence of their mutual Coulomb interaction. The device consists of interacting quantum dots coupled to spin-polarized leads via quantum point contacts with Rashba interaction. The Rashba spin-flip-assisted inter-subband mixing in quantum point contacts induces quantum interference between the tunneling waves, which interact by Coulomb repulsion inside the dot. The spin-dependent Fano resonances, which appear in the conductance through the device, are significantly modified by Coulomb interactions. Their width and shape depend on the quantum dot spin-up and spin-down occupancies, controlled by electron interactions. On the other hand, correlators calculated for the quantum dot spin sub-levels are not influenced by quantum interference between them and depend rather on the degree of localization of these levels.