Domain wall in a chiral p-wave superconductor: a pathway for electrical current

TL;DR

This paper demonstrates that domain walls in chiral p-wave superconductors can serve as one-way channels for electrical current, providing a novel method to detect topological superconductivity despite magnetic screening effects.

Contribution

It introduces a theoretical framework showing domain walls as charge transport pathways and derives a conductance product rule for identifying topological superconductors.

Findings

Domain walls act as unidirectional charge channels.

A product rule for conductance cancels tunnel barrier effects.

Provides a signature for topological superconductivity.

Abstract

Superconductors with p+ip pairing symmetry are characterized by chiral edge states, but these are difficult to detect in equilibrium since the resulting magnetic field is screened by the Meissner effect. Nonequilibrium detection is hindered by the fact that the edge excitations are unpaired Majorana fermions, which cannot transport charge near the Fermi level. Here we show that the boundary between p_x+ip_y and p_x-ip_y domains forms a one-way channel for electrical charge. We derive a product rule for the domain wall conductance, which allows to cancel the effect of a tunnel barrier between metal electrodes and superconductor and provides a unique signature of topological superconductors in the chiral p-wave symmetry class.