Magnetic orbital motion and 0.5$e^2/h$ conductance of quantum-anomalous-Hall hybrid strips

Abstract

The magnetic-induced orbital motion of quasiparticles affects the conductance properties of a hybrid strip of a quantum-anomalous-Hall topological material with induced superconductivity. We elucidate the scenario of topological NSN ideal junctions in presence of orbital magnetic motion, showing how it leads to a halved quantized conductance $0.5e^2/h$ even in absence of Majorana modes. The magnetic orbital effect favours Fermionic charged modes with finite wave numbers, in contradistinction to Majorana zero modes which are chargeless zero-energy modes with vanishing wave number. The bias sensitivity of the 0.5 conductance plateau allows to distinguish the two cases. Conductance oscillations due to backscattering interference are absent in the charged Fermion case.