Tunneling limit of heavy-fermion point contacts

Abstract

We present results for a multichannel tunneling model that describes point-contact spectra between a metallic tip and a superconducting heavy-fermion system. We calculate tunneling spectra both in the normal and superconducting state. In point-contact and scanning tunneling spectroscopy many heavy-fermion materials, like CeCoIn5, exhibit an asymmetric differential conductance, dI/dV, combined with a strongly suppressed Andreev reflection signal in the superconducting state. For Andreev reflection to occur a junction has to be in the highly transparent limit. Here we focus on the opposite limit, namely that of low transparency leading to BCS-like dI/dV curves. We discuss the consequences of a multichannel tunneling model for CeCoIn5 assuming itinerant electron bands and localized f electrons.

Contribution at SCES-2010

References in corpus (6)

• Fermi-liquid instabilities at magnetic quantum phase transitions
• Imaging the Fano Lattice to 'Hidden Order' Transition in URu2Si2
• Andreev Reflection in Heavy-Fermion Superconductors and Order Parameter Symmetry in CeCoIn_5
• Universal Behavior in Heavy Electron Materials
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Cited by in corpus (1)

• Origin of gap-like behaviors in URu${}_2$Si${}_2$: Combined study via quasiparticle scattering spectroscopy and resistivity measurements