Anomalous zero bias conductance peaks in a graphene-based ferromagnet/insulator/p-wave superconductor hybrid structure

Abstract

We theoretically study graphene-based ferromagnet/insulator/p-wave superconductor hybrid structure, where an anomalous zero bias conductance peak (ZBCP) is exhibited. With the exchange field h increased, the zero-bias conductance dips (ZBCDs) for both the px- and py-wave situations develop into ZBCPs at h∕EF>1, which are just contrary to the situation at h∕EF<1. Furthermore, with the enhancement of barrier strength χ, the conversion from the ZBCD to ZBCP is displayed in the region of h∕EF>1 for the px-wave, whereas the sharp ZBCP remains all the time at any h for the py-wave. More interestingly, the zero-bias conductance for the px-wave keeps unchanged upon increasing χ, while for the py-wave, exhibits periodical modulation of χ. The singular features can be used to not only identify the p-wave superconductivity and spin polarization in graphene but also pave the way to a new class of tunable superconducting spintronic devices based on large-scale graphene.