Structure of the core of magnetic vortices in d-wave superconductors with a subdominant triplet pairing mechanism

TL;DR

This paper investigates the unconventional core structure of magnetic vortices in high-temperature cuprate superconductors, proposing a mixed parity [d + i p]-wave order parameter that explains the absence of zero-energy states.

Contribution

It introduces a model where a subdominant triplet pairing mechanism leads to a mixed parity vortex core state, differing from conventional vortex core spectra.

Findings

Vortex cores exhibit a [d + i p]-wave order parameter.

Zero-energy quasiparticle states are absent in the core.

The proposed model explains experimental spectral observations.

Abstract

The quasiparticle states found in the vortex core of a high-T$_{\rm{c}}$ cuprate superconductor may be probed by scanning tunneling spectroscopy. Results of such experiments have revealed typical spectra that are quite different from what is seen in conventional low-Tc superconductors. In particular the Caroli-deGennes-Matricon state at $E\sim 0$ in the core center is not seen. Instead, in a high-T$_{\rm{c}}$ vortex core, quasiparticle states are found at energies that are at a sizable fraction of the gap energy. One explanation for this could be that a finite amplitude of a competing orderparameter stabilizes in the vortex-core center. Here I will explore the possibility of nucleating a vortex-core state that locally breaks inversion symmetry. The vortex-core orderparameter is of mixed parity, a $[d + i p]$-wave, and the quasiparticle spectra in the core center lacks the E=0 states.