Finite length effect on supercurrents between trivial and topological superconductors

TL;DR

This paper investigates how the finite length of superconducting regions influences the low-energy spectrum and supercurrents in junctions between trivial and topological superconductors, revealing indicators of Majorana states.

Contribution

It provides a numerical analysis of finite length effects on supercurrents and spectral properties, highlighting their role as signatures of topological phases and Majorana bound states.

Findings

Supercurrent and spectrum strongly depend on topological segment length.

Finite length effects serve as indicators of topological phase transitions.

Emergence of Majorana bound states correlates with specific spectral features.

Abstract

We numerically analyze the effect of finite length of the superconducting regions on the low-energy spectrum, current-phase curves, and critical currents in junctions between trivial and topological superconductors. Such junctions are assumed to arise in nanowires with strong spin-orbit coupling under external magnetic fields and proximity-induced superconductivity. We show that all these quantities exhibit a strong dependence on the length of the topological sector in the topological phase and serve as indicators of the topological phase and thus the emergence of Majorana bound states at the end of the topological superconductor.