Multiple topological transitions driven by the interplay of normal scattering and Andreev scattering

TL;DR

This paper uncovers multiple topological transitions in semiconducting nanowires with vortices, driven by the interplay of normal and Andreev scattering, revealing new quasiparticle modes and transport phenomena relevant for Majorana states.

Contribution

It introduces a novel mechanism for multiple topological transitions in proximitized nanowires, emphasizing the role of textured spin-orbit coupling and scattering processes.

Findings

Identification of multiple topological transitions in nanowires

Discovery of unique charge and spin transport signatures

Analysis of Majorana and evanescent quasiparticle modes

Abstract

The effect of multiple topological transitions for electron-hole excitations is discovered in full shell proximitized semiconducting nanowires with trapped superconducting vortices, recently shown to be a promising platform for the realization of Majorana states at moderate longitudinal magnetic fields. The mechanism of such multiple transitions is uncovered and explained to be governed by the interplay of normal and Andreev reflections from the shell and by the textured spin-orbit coupling inside the semiconductor. The extensive analysis of emerging propagating and Majorana-type evanescent quasiparticle modes in such Andreev waveguides is performed. Experimentally, these modes reveal themselves in peculiarities of charge and spin-polarized heat transport.