Gapless Topological Superconductors - Model Hamiltonian and Realization

TL;DR

This paper introduces a new class of 2D topological superconductors with gapless bulk spectra but localized Majorana edge states, supported by model analysis and potential realization on topological insulators.

Contribution

It proposes a novel family of Hamiltonians for gapless bulk topological superconductors with edge Majorana states and suggests a physical realization involving magnetic impurities.

Findings

Model Hamiltonian exhibits gapless bulk and localized edge states.

Numerical analysis confirms the topological phase characteristics.

Potential realization on topological insulator surfaces with magnetic impurities.

Abstract

The existence of an excitation gap in the bulk spectrum is one of the most prominent fingerprints of topological phases of matter. In this paper, we propose a family of two dimensional Hamiltonians that yield an unusual class $D$ topological superconductor with a gapless bulk spectrum but well-localized Majorana edge states. We perform a numerical analysis for a representative model of this phase and suggest a concrete physical realization by analyzing the effect of magnetic impurities on the surface of strong topological insulators.