Topological pumping in class-D superconducting wires

TL;DR

This paper investigates topological charge pumping in a nanowire-superconductor system with non-uniform superconductivity, revealing quantized charge transfer linked to the system's topological phases.

Contribution

It demonstrates that in a spin-orbit coupled nanowire with non-uniform induced superconductivity, the pumped charge is quantized and topologically protected.

Findings

Pumped charge is quantized in units of e.

Topological phases are characterized by isolated trivial regions.

Charge pumping is robust against certain perturbations.

Abstract

We study adiabatic pumping at a normal metal/class-D superconductor hybrid interface when superconductivity is induced through the proximity effect in a spin-orbit coupled nanowire in the presence of a tilted Zeeman field. When the induced order parameter in the nanowire is non-uniform, the phase diagram has isolated trivial regions surrounded by topological ones. We show that in this case the pumped charge is quantized in units of the elementary charge $e$ and has a topological nature.