Point-contact spectroscopy of the heavy-fermion superconductor CePt$_{3}$Si

TL;DR

This study uses point-contact spectroscopy to investigate the differential resistance of CePt$_{3}$Si, revealing zero-bias peaks that may be linked to magnetic or crystal field effects, independent of magnetic transition temperatures.

Contribution

It provides new insights into the electronic scattering processes in CePt$_{3}$Si through point-contact spectroscopy, highlighting features similar to other heavy-fermion superconductors.

Findings

Zero-bias peaks observed in differential resistance spectra.

Peak width possibly related to crystal field splitting or spin-wave gap.

Peak evolution occurs above the antiferromagnetic transition temperature.

Abstract

Differential resistance spectra (${\rm d}V/{\rm d}I-V$ characteristics) have been measured for point-contacts between the heavy-fermion superconductor (HFS) CePt$_{3}$Si and a normal metal. Some contacts show a peak at V=0 that is characteristic of HFS coexisting with a magnetic order such as UPd$_2$Al$_3$, UNi$_2$Al$_3$ and URu$_2$Si$_2$. The evolution of the peak occurs well above the antiferromagnetic transition temperature $T_{{\rm N}}\sim$ 2.2 K, so that the direct relationship with the magnetic transition is questionable. The half-width of the peak seems to reflect the crystal field splitting or the spin-wave gap as observed for the above-mentioned HFSs, possibly suggesting that some common scattering process induces the zero-bias peaks in these materials.