Speaker
Description
Majorana bound states (MBS) appear as topologically protected edge states in certain topological superconductors. The prototypical example is the one-dimensional Kitaev model with spinless p-wave superconductivity. Both spin-orbit coupled semiconductor-superconductor nanowire systems or chains of magnetic atoms deposited on a superconducting surface are considered to emulate this topological superconducting state. In this talk I will present a few of our recent theoretical findings on how the topological superconducting phase and its MBS can be enhanced by small modifications of the experimental setups, both in terms of the gap protecting the MBS and the available phase diagram for achieving topological superconductivity.
In particular, I will show how a quasicrystal arrangement of a magnetic atom chain generates an intriguing interplay between quasiperiodicity and topological superconductivity, with an enlarged topological superconducting domain and more robust MBS. In addition, I will show how MBS survive and can even be created in nanowires in the strong dissipative regime, but that non-Hermitian exceptional points also produce trivial zero-energy states. Finally, I will show how non-Hermitian effects can be used to obtain dramatically more robust MBS due to an extreme sensitivity of superconductivity at certain exceptional points. These results also generally point to how topological phases of matter can interact with a varying environment.
