Development of Point-Contact Spectroscopy of Heavy-Fermion Superconductors under Pressure

We have developed a new method to perform point-contact spectroscopy PCS under pressure, in which a thin-film deposition technique is used for making a point contact. We investigated a pressure dependence of the point-contact spectra of the heavy-fermion superconductor URu2Si2 single crystal. In PCS of URu2Si2, two characteristic components evolve at low temperatures: one is a symmetric structure with respect to zero bias voltage suggesting a gap of the density of states at the Fermi surface, and the other is an anti-symmetric structure. We observed little change of two components between hidden order and antiferromagnetic phases.