Electrostatic effects and topological superconductivity in semiconductor-superconductor-magnetic insulator hybrid wires

TL;DR

This paper studies how electrostatic effects influence topological superconductivity in hybrid semiconductor-superconductor-magnetic insulator wires, revealing that overlapping layers and electrostatics are crucial for achieving the desired topological phase.

Contribution

It demonstrates that electrostatic effects significantly impact the emergence of topological superconductivity, especially in structures with overlapping magnetic insulator and superconductor layers.

Findings

Large Zeeman fields emerge in overlapping layer structures.

Electrostatics determine wave function amplitudes near interfaces.

Topological superconductivity is achievable within a specific parameter window.

Abstract

We investigate the impact of electrostatics on the proximity effect between a magnetic insulator and a semiconductor wire in semiconductor-superconductor-magnetic insulator hybrid structures. By performing self-consistent Schr$\ddot{\rm o}$dinger-Poisson calculations using an effective model of the hybrid system, we find that large effective Zeeman fields consistent with the emergence of topological superconductivity emerge within a large parameter window in wires with overlapping layers of magnetic insulator and superconductor, but not in non-overlapping structures. We show that this behavior is essentially the result of electrostatic effects determining the amplitude of the low-energy wave functions near the semiconductor-magnetic insulator interface.