Scanning tunneling microscopy and spectroscopy measurements of heavy fermion compound CeCoIn$_{5}$

ORAL

Abstract

The heavy fermion compound CeCoIn$_{5}$ has a rich electronic phase diagram as a function of doping, pressure, and magnetic field. The interaction between Ce's f-electrons and the conduction bands is expected to form Kondo screening of the spins starting at relatively high temperatures. Below 2.3 K CeCoIn$_{5}$ is known to exhibit an unconventional superconducting ground state. We present scanning tunneling microscopy and spectroscopy (STM/S) as a function of temperature on CeCoIn$_{5}$. The in-situ cleaved samples show three different layer terminations. Acquiring structural information from STM topographies we identify the chemical character of each layer. STS measurements, on all surfaces, performed over a wide range of temperature show the rapid development of an energy gap in the tunneling density of states near the onset of coherence ($\sim $ 40 K). The origin of the observed energy gap and its relation to heavy band hybridization is addressed.

–

Authors

  • Eduardo da Silva Neto

    Princeton University

  • Pegor Aynajian

    Princeton University

  • Colin Parker

    Brookhaven National Laboratory, Princeton University

  • Paul Tobash

    Los Alamos National Laboratory

  • Eric Bauer

    Los Alamos Natl. Lab., NM, USA, Los Alamos National Lab, MPA-CMMS, Los Alamos Nat. Lab., MPA-CMMS, Los Alamos National Laboratory, Los Alamos, NM 87545, USA, Los Alamos National Laboratory, Los Alamos National Laboratory, Los Alamos, NM 87545

  • Ali Yazdani

    Department of Physics, Princeton University, Physics Department, Princeton University, Princeton University