Topologically Tuned Obliquity of Klein-Tunnelling Charged Currents Through Graphene Electrostatically-Confined p − n Junctions

Abstract

Problem of control over Klein-tunnelling states from electrostatically-confined graphene p − n junctions has been discussed. The lack of quasi-bound states, being the states with a finite life time, in a pseudo-Dirac-fermion model for the graphene quantum dot (GQD) is theoretically predicted as inapplicability of the so-called “resonance condition” leading to an inconsistent linear system corresponding to matching conditions. Within a pseudo-Dirac-Weyl fermion model GQD, the graphene charge carriers are topologically nontrivial and can be confined by a staircase-type potential due to competition between Zak curvature and centrifugal-force actions. The predicted topological effects elucidate experimentally observed resonances created by electron beam and laser pulse in crystalline arrays of single-walled carbon nanotubes as the Klein-tunnelling resonant states in the p − n graphene junctions. We present a robust approach to fabricate stable graphene p−n junctions by fine-tuning the topological effects.