Heavy-fermion metals with hybridization nodes: Unconventional Fermi liquids and competing phases

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Heidrun Weber - , University of Cologne (Author)
  • Matthias Vojta - , University of Cologne (Author)

Abstract

Microscopic models for heavy-fermion materials often assume a local, i.e., momentum-independent, hybridization between the conduction band and the local-moment f electrons. Motivated by recent experiments, we consider situations where this neglect of momentum dependence is inappropriate, namely, when the hybridization function has nodes in momentum space. We explore the thermodynamic and optical properties of the highly anisotropic heavy Fermi liquid, resulting from Kondo screening in a higher angular-momentum channel. The dichotomy in momentum space has interesting consequences: while, e.g., the low-temperature specific heat is dominated by heavy quasiparticles, the electrical conductivity at intermediate temperatures is carried by unhybridized light electrons. We then discuss aspects of the competition between Kondo effect and ordering phenomena induced by intermoment exchange. We propose that the strong momentum-space anisotropy plays a vital role in selecting competing phases. Explicit results are obtained for the interplay of unconventional hybridization with unconventional, magnetically mediated, superconductivity, utilizing variants of large- N mean-field theory. We make connections to recent experiments on CeCo In5 and other heavy-fermion materials.

Details

Original languageEnglish
Article number125118
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume77
Issue number12
Publication statusPublished - 13 Mar 2008
Peer-reviewedYes
Externally publishedYes