Ab initio study of 1D topological superconductors

Magnetic chains manufactured on superconducturs are possible candidates for fault tolerant qunatum computing architectures. Due to the interplay of magnetism, superconductivity and spin-orbit coupling these systems are suitable to promote the formation of topologically protected zero energy end states, the so-called Majorana Zero Modes (MZM). The signatures of MZMs can be studied both experimentally and theoretically by investigating the spectrum of finite chains, as done recently for systems like Fe/Re(1000), Fe/Pb(001), Mn/Nb(110), Fe/Au/Nb(110), Mn/Ta(110). However, the topological properties of the band structure can't be measured directly, and it is also not accessible in terms of calculations for finite chains.

In the present talk I will introduce an ab inito method suitable to study infinite chains by employing a one-dimensional embedding technique within the Korringa-Kohn-Rostoker Green's function method solving the fully relativistic Bogoliubov-de Gennes equations. This method provides a unique picture to understand the topological properties of the band structure of infinite chains. I will show the calculated band structures and compare them with the quasiparticle interference spectra for systems well studied in the literature like Mn/Nb(110), Fe/Au/Nb(110) and Mn/Ta(110).