Unconventional superconductivity in the strong-coupling limit for the heavy fermion system CeCoIn5

Y. FASANO; P. SZABO; J. KACMARCIK; Z. PRIBULOVA; P. PEDRAZZINI; P. SAMUELY; V. CORREA

Praga

Conferencia; Poster (presentado por colegas) en la International Conference on Strongly Correlated Electronic Systems (SCES 2017); 2017

Charles University, Praga

CeCoIn5 is a heavy-fermion superconductor (Tc = 2.2 K) with superconductivity nucleating in concomitance with magnetic order. Here we present scanning tunneling spectroscopy measurements of the quasiparticle excitation spectrum of CeCoIn5 between 400 mK and 3 K. For temperatures T< Tc the spectra can be fitted reasonably well considering a d-wave symmetry of the superconducting gap Δ. The obtained ratio 2Δ/kTc ~ 6 indicates that CeCoIn5 is an unconventional superconductor in the strong coupling limit. In striking parallel with cuprate superconductors, the tunneling conductance shows a depletion at energies smaller than Δ for temperatures larger than Tc, suggesting the existence of a pseudogap phase up to 1.25Tc.