Fano and Dicke effects in a double Rashba-ring system

Abstract

The electronic transport in a system of two quantum rings side-coupled to a quantum wireis studied via a single-band tunneling tight-binding Hamiltonian. We derivedanalytical expressions for the conductance and spin polarization when the rings arethreaded by magnetic fluxes with Rashba spin–orbit interaction. We show that byusing the Fano and Dicke effects this system can be used as an efficient spinfilter even for small spin–orbit interaction and small values of magnetic fluxes.We compare the spin-dependent polarization of this design and the polarizationobtained with one ring side-coupled to a quantum ring. As a main result, wefind better spin polarization capabilities as compared to the one-ring design.