Novel features in the flux-flow resistivity of the heavy fermion superconductor PrOs$_{4}$Sb$_{12}$

TL;DR

This study reveals unusual double minima in flux-flow resistivity of PrOs$_{4}$Sb$_{12}$, linked to complex pinning force behavior and multiple superconducting phases, advancing understanding of heavy fermion superconductor properties.

Contribution

First observation of double minima in flux-flow resistivity and field-direction dependent pinning force in PrOs$_{4}$Sb$_{12}$, indicating complex vortex dynamics and multiple SC phases.

Findings

Double minima in flux-flow resistivity as a function of magnetic field.

Pinning force density exhibits two-fold and four-fold symmetry.

Correlation between flux-flow resistivity features and multiple superconducting phases.

Abstract

We have investigated the electrical resistivity of the heavy fermion superconductor PrOs$_{4}$Sb$_{12}$ in the mixed state. We found unusual double minima in the flux-flow resistivity as a function of magnetic field below the upper critical field for the first time, indicating double peaks in the pinning force density ($F_{\rm P}$). Estimated $F_{\rm P}$ at the peak exhibits apparent dependence on applied field direction; composed of two-fold and four-fold symmetries mimicking the reported angular dependence of thermal conductivity ($\kappa$). The result is discussed in correlation with the double step superconducting (SC) transition in the specific heat and the multiple SC-phases inferred from the angular dependence of $\kappa$.