Discounted Fano effect induced by the quantum interference between two Andreev reflection channels: nonequilibrium Green’s function calculations

We concentrate on the Fano effect in the Andreev reflection spectra of a two-arm three-terminal normal/superconducting (NS) heterojunction, in which one normal metallic lead is coupled to two s-wave superconducting leads via respective quantum dots. It is found that if an arm of this system provides the reference channel for the Andreev reflection, Fano antiresonance is allowed to appear in the differential conductance spectrum. Superconducting phase difference between the superconducting leads plays its nontrivial role in modulating the Fano lineshapes in the conductance spectra. However in the linear conductance spectra, Fano lineshapes are relatively weak and not related to any antiresonance point, though they can be reversed by adjusting the dot level of the reference channel. It can be believed that the results of this work will help to understand the Fano interference in the Andreev reflection driven by two respective superconducting leads.