Straining the Identity of Majorana Fermions

Abstract

We propose an experimental setup of an interferometer for the observation of neutral Majorana fermions on topological insulator - superconductor - ferromagnet junctions. We show that the extended lattice defects naturally present in materials, dislocations, induce spin currents on the edges while keeping the bulk time-reversal symmetry intact. We propose a simple two terminal conductance measurement in an interferometer formed by two edge point contacts, which reveals the nature of Majorana states through the effect of dislocations. The zero temperature magneto-conductance changes from even oscillations with period phi/2 (phi is the flux quantum hc/e) to odd oscillations with period phi, when non-trivial dislocations are present and the Majorana states are sufficiently strongly coupled. Additionally, the conductance acquires a notable asymmetry as a function of the incident electron energy, due to the topological influence of the dislocations, while resonances appear at the coupling energy of Majorana states.