Point-contact spectroscopy of the heavy-fermion superconductor CePt${}_3$Si

Abstract

Differential resistance spectra ($\mathrm{d}V/\mathrm{d}I-V$ 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 $T_{\mathrm{N}}\sim$ 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.

9 pages, 5 figures, To be published in J. Phys.: Condens. Matter