Effect of uniaxially anisotropic Fermi surface on the quasiparticle scattering inside a vortex core in unconventional superconductors

TL;DR

This study theoretically examines how uniaxial anisotropy of the Fermi surface influences quasiparticle scattering rates within vortex cores of unconventional superconductors, revealing increased sensitivity to pair potential sign changes with higher system two-dimensionality.

Contribution

It introduces a theoretical analysis of the impact of Fermi surface anisotropy on quasiparticle scattering, highlighting the enhanced detection of pair potential sign changes in more two-dimensional systems.

Findings

Scattering rate depends on magnetic field angle and Fermi surface anisotropy.

Higher two-dimensionality enhances the sensitivity of scattering rate to pair potential sign change.

Field-angle dependence of scattering rate can indicate the presence of sign-changing pair potentials.

Abstract

We theoretically study the dependence of the quasiparticle (QP) scattering rate $\varGamma$ on the uniaxial anisotropy of a Fermi surface with changing the magnetic field angle $\alpha_{\rm M}$. We consider the QP scattering due to the non-magnetic impurities inside a single vortex core. The field-angle dependence of the quasiparticle scattering rate $\varGamma(\alpha_{\rm M})$ is sensitive to the sign-change of the pair potential. We show that with increasing the two dimensionality of the system, $\varGamma(\alpha_{\rm M})$ reflects more clearly whether there is the sign-change in the pair potential.