The vortex core excitation spectrum in gapped topological d-wave superconductors

TL;DR

This paper investigates the excitation spectrum of vortices in gapped topological d-wave superconductors using Bogoliubov-deGennes equations, revealing unique core excitation modes that influence thermal and vortex behaviors.

Contribution

It provides a simplified theoretical framework for analyzing vortex core excitations in gapped chiral d-wave superconductors with implications for thermal transport and vortex dynamics.

Findings

Core has a single excitation mode per momentum value.

Excitation spectrum differs from conventional superconductors.

Impacts thermal transport and vortex behavior.

Abstract

There are indications that some high temperature unconventional superconductors have a "complex" d-wave order parameter (with an admixture of s-wave) leading to nonzero energy gap. Since the coherence length is short and the Fermi energy is relatively small the quasiclassical approach is inapplicable and the more complicated Bogoliubov-deGennes equations should be used to investigate the excitation spectrum of such a material in a magneric field. It turns out that equations for the gapped chiral d-wave superconductor, simplify considerably and is the basis for any superconductor of that type with a sufficiently large gap. The spectrum of core excitations of the Abrikosov vortex in an anisotropic 3D sample exhibits several features. Unlike in conventional and gapless superconductors the core has a single excitation mode of order energy gap for each value of momentum along the field. This has a large impact on thermal transport and vortex dynamics.