Chain of Majorana States from Superconducting Dirac Fermions at a Magnetic Domain Wall

TL;DR

This paper theoretically demonstrates that magnetic domain walls in a 2D superconductor with Dirac fermions can host chains of Majorana states, with their properties tunable by the chemical potential.

Contribution

It introduces a novel mechanism for creating Majorana chains using magnetic domain walls in superconducting Dirac systems, highlighting tunability via chemical potential.

Findings

Magnetic domain walls host chains of Majorana fermions.

Overlap of Majorana states depends on chemical potential.

Thermal conductivity shows V-shaped dependence on chemical potential.

Abstract

We study theoretically a strongly type-II s-wave superconducting state of two-dimensional Dirac fermions in proximity to a ferromagnet having in-plane magnetization. It is shown that a magnetic domain wall can host a chain of equally spaced vortices in the superconducting order parameter, each of which binds a Majorana fermion state. The overlap integral of neighboring Majorana states is sensitive to the position of the chemical potential of the Dirac fermions. This leads to a characteristic V-shaped dependence of thermal conductivity of Majorana fermions on the chemical potential.