Very Low Temperature Tunnelling Spectroscopy in the heavy fermion superconductor PrOs$_4$Sb$_{12}$

TL;DR

This study uses tunnelling spectroscopy to investigate the superconducting gap in PrOs$_4$Sb$_{12}$, revealing a large gap opening with deviations from simple BCS behavior, indicating complex gap structure.

Contribution

First detailed tunnelling spectroscopy analysis of PrOs$_4$Sb$_{12}$ showing a large, non-isotropic superconducting gap.

Findings

Superconducting gap opens over a large part of the Fermi surface.

Deviations from isotropic BCS s-wave behavior observed.

Finite distribution of gap values suggests complex pairing symmetry.

Abstract

We present scanning tunnelling spectroscopy measurements on the heavy fermion superconductor PrOs$_4$Sb$_{12}$. Our results show that the superconducting gap opens over a large part of the Fermi surface. The deviations from isotropic BCS s-wave behavior are discussed in terms of a finite distribution of values of the superconducting gap.