We theoretically present an anomalous zero bias conductance peak (ZBCP) in graphene junctions with proximity-induced ferromagnetism and d-wave anisotropic superconducting pair symmetry (ASPS) herein. It is revealed that in the thin insulator limit, the ZBCP can be periodically recovered by adjusting the sandwiched insulating barrier strength χ regardless of exchange field h and the phase of the periodical behaviours for h larger than its Fermi energy EF (h > EF) is exactly opposite to that for h < EF. Most interestingly, in the context of h > EF, the periodic oscillation of the nonzero bias conductance located in the ZBCP versus χ, is accompanied by an explicit splitting peak. Moreover, under the situation of the insulator with finite width, the conductance exhibits a stronger damping oscillation with bias voltage eV for any h, which is also accompanied by a splitting ZBCP at h > EF. These singular features originate from ferromagnetic-modulated midgap states characteristic by the relativistic nodal fermions, which confirms the spin polarization and ASPS of the graphene, and thus will be of great interest in the designing and fabrication of graphene superconducting spintronic devices.
We theoretically investigate the subgap transport in a ferromagnetic silicene/superconductor junction and highlight the role of the interface. It is demonstrated that the subgap conductance spectra for the continuous and discontinuous interface models are significantly different. In particular, the intravalley Andreev reflection (AR) may occur at the discontinuous interface, and then the subgap conductance will be remarkably enhanced when the silicene sheet is highly valley polarized. This novel AR resulted from the valley-mixing scattering, which is absent in the continuous interface model. The influence of the interface coupling strength on the subgap conductance is also computed. Our results can be directly tested experimentally using scanning tunnel microscope measurements and/or point-contact spectroscopy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.