Robust Majorana bound state in pseudospin domain wall of a two-dimensional topological insulator

Abstract

We investigate helical edge states emerging at the composite domain wall of spin and pseudospin degrees of freedom in a two-dimensional (2D) bulk governed by the Bernevig-Hughes-Zhang Hamiltonian which underwent quantum spin Hall to anomalous Hall transition. We numerically study the stability of Majorana bound states (MBSs) formed due to proximity-induced superconductivity in these helical edge states. We establish the robustness of MBSs against moderate chemical potential or magnetic disorder owing to the existence of the simultaneous orthogonality between the right and the left moving modes in both spin and pseudospin space. Hence our proposal could pave the way to realizing robust Majorana bound states on 2D platforms.