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The Andreev reflection of the normal state-superconductor junction both in monolayer and bilayer graphene with a single magnetic barrier is investigated by means of the Greens function formalism. Within the tight-binding model, we study the direction-dependent Andreev reflection of two-dimensional graphene-superconductor junctions in the specular and retro-reflection regimes. The presence of a magnetic barrier close to the superconducting hybrid junction introduces a rich phenomenology. Such a barrier is capable of tuning the preferred angles of incidence for the Andreev reflection. In particular, it can enhance the specular reflection probability for certain angles of incidence in bilayer-based hybrid structures. When transmission is permitted, the Andreev reflection manifests itself in isolated peaks and asymmetric resonances associated with offsets and Fano-type oscillations in the transmission, respectively. Moreover, Fabry-P{e}rot oscillations in the Andreev reflection due to the interior scattering inside the magnetic barrier may appear. The impacts of magnetic barriers on the monolayer and bilayer hybrid interfaces are furthermore studied by calculating the differential conductances within the Blonder-Tinkham-Klapwijk formula.
We report the study of ballistic transport in normal metal/graphene/superconductor junctions in edge-contact geometry. While in the normal state, we have observed Fabry-P{e}rot resonances suggesting that charge carriers travel ballistically, the supe
Using the non-equilibrium Green function method, we study the Andreev reflection in a Y-shaped graphene-superconductor device by tight-binding model. Considering both the zigzag and armchair terminals, we confirm that the zigzag terminals are the bet
We study Andreev reflection in graphene nanoribbon/superconductor hybrid junctions. By using a tight-binding approach and the scattering formalism we show that finite-size effects lead to notable differences with respect to the bulk graphene case. At
Coherent charge transport along ballistic paths can be introduced into graphene by Andreev reflection, for which an electron reflects from a superconducting contact as a hole, while a Cooper pair is transmitted. We use a liquid-helium cooled scanning
Andreev reflection in graphene is special since it can be of two types- retro or specular. Specular Andreev reflection (SAR) dominates when the position of the Fermi energy in graphene is comparable to or smaller than the superconducting gap. Bilayer