Fano-Rashba effect in a double quantum dot Aharonov-Bohm interferometer

Abstract

The interplay between the Fano and Rashba spin-orbit (RSO) effects in an Aharonov-Bohm (AB) interferometer containing two noninteracting quantum dots (QDs) in each of its arms is studied by employing the Green’s function equation of motion. When electrons flow through the upper and lower arms of the interferometer, the RSO interaction in the QDs induces a spin-dependent phase factor in the linewidth matrix elements. By the co-action of this phase factor and the magnetic flux penetrating the AB ring, an interesting spin-dependent Fano effect will arise. It is found that the Fano line shapes of the two spin components in the conductance spectra can be tuned either synchronously or individually with the help of the structure parameters relevant to the RSO coupling strength, magnetic flux, and the structure configuration. We focus our attention on the manipulation of the swap operation of the resonances centered at the bonding and antibonding energies, spin-flip processes, and the broadening of the resonances, which might have practical applications in spintronics devices. We also find that both the broadening of the resonances and the spin polarization efficiency can be controlled in terms of the dot-lead coupling strength.