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UBC Theses and Dissertations

Superconducting d+id order parameter supports Majorana bound states Mercado Tejerina, Alejandro Miguel

Abstract

Majorana-bound states (MBS) are quasiparticles that are created by the collective excitations of electrons in a material. Liang Fu and Charles Kane realized in 2008 that such quasi-particles can exist in the interface of a strong topological insulator and an s-wave superconductor. In this thesis, we take a look at the model proposed by Fu and Kane (later mentioned as the ”Fu-Kane model”) and realize instead of an s-wave superconductor a d+id-wave superconductor works just as well. It has been shown that there exist high-temperature superconductors with a d+id superconducting order, thus the advantage of this approach would be to have Majorana bound states at high temperatures. We, in this thesis, give both an analytical approach to this model as well as simulations, which indicate the existence of MBS in this system. Such topological insulators and superconductors have already been studied with examples of Bi₂Se₃ and twisted Bi₂Sr₂CaCu₂O₈₊δ respectively.