Point-contact spectroscopy of the heavy-fermion superconductor CePt3Si

Differential resistance spectra (dV/dI-V characteristics) have been measured for point contacts between the heavy-fermion superconductor (HFS) CePt3Si and a normal metal. Some contacts show a peak at V = 0 that is characteristic of HFS coexisting with a magnetic order such as UPd2Al3, UNi2Al3 and URu2Si2. The evolution of the peak occurs well above the antiferromagnetic transition temperature TN∼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.