Field-angle Resolved Flux-flow Resistivity as a Phase-sensitive Probe of Unconventional Cooper Pairing

TL;DR

This paper proposes a phase-sensitive method using field-angle dependent flux-flow resistivity measurements to detect sign changes in the superconducting pair potential, providing insights into unconventional pairing symmetries.

Contribution

The study introduces a theoretical framework linking flux-flow resistivity anisotropy to the sign change in the superconducting gap, enabling phase-sensitive detection.

Findings

Flux-flow resistivity peaks when magnetic field aligns with gap nodes.

Resistivity's angular dependence reveals pair potential sign changes.

Method offers a new way to probe unconventional superconductivity.

Abstract

We theoretically investigate the applied magnetic field-angle dependence of the flux-flow resistivity $\rho_{\rm f}(\alpha_{\rm M})$ for an uniaxially anisotropic Fermi surface. $\rho_{\rm f}$ is related to the quasiparticle scattering rate $\varGamma$ inside a vortex core, which reflects the sign change in the superconducting pair potential. We find that $\rho_{\rm f}(\alpha_{\rm M})$ is sensitive to the sign-change in the pair potential and has its maximum when the magnetic field is parallel to the gap-node direction. We propose the measurement of the field-angle dependent oscillation of $\rho_{\rm f}(\alpha_{\rm M})$ as a phase-sensitive field-angle resolved experiment.