Giant tunable magnetoresistance of electrically gated graphene ribbon with lateral interface under magnetic field

Quantum dynamics and kinetics of electrically gated graphene ribbons with lateral n–p and n–p–n junctions under magnetic field are investigated. It is shown that the snake-like states [C. W. J. Beenakker, Rev. Mod. Phys. 80, 1337 (2008)] of quasiparticles skipping along the n–p interface do not manifest themselves in the main semi-classical part of the ribbon conductance. Giant oscillations of the conductance of a ribbon with an n–p–n junction are predicted and analytically calculated. Depending on the number of junctions inside the ribbon its magneto-resistance may be controllably changed by 50%–90% by an extremely small change of the magnetic field or the gate voltage.