Point-contact Spectroscopy of Heavy Fermion Superconductors Ce2PdIn8 and Ce3PdIn11 in Comparison with CeCoIn5.

We report point-contact spectroscopy measurements on heavy fermion cousins CeCoIn5 , Ce2PdIn8 and Ce3PdIn11 to systematically study the hybridization between f and conduction electrons. Below a temperature T∗ , the spectrum of each compound exhibits an evolving Fano-like conductance shape, superimposed on a sloping background, that suggests the development of hybridization between local f and itinerant conduction electrons in the coherent heavy fermion state below T∗ . We present a quantitative analysis of the conductance curves with a two-channel model to compare the tunneling process between normal metallic silver particles in our soft point-contact and heavy-fermion single crystals CeCoIn5 , Ce2PdIn8 and Ce3PdIn11 .