Electronic tuning in CeCoIn5: A dirty job

Filip Ronning

Los Alamos National Laboratory, USA


    Superconductivity in the Ce and Pu-based 115’s is strongly believed to have a gap structure with dx2-y2 symmetry. Impurities are known to be a microscopic probe of strongly correlated materials. We report a globally reversible effect of electronic tuning on the magnetic phase diagram in CeCoIn5 driven by electron (Pt and Sn) and hole (Cd, Hg) doping. Consequently, we are able to extract the superconducting pair breaking component for hole and electron dopants with pressure and co-doping studies, respectively. We find that these nominally non-magnetic dopants have a remarkably weak pair breaking effect for a $d$-wave superconductor. The pair breaking is weaker for hole dopants which induce magnetic moment than for electron dopants. Furthermore, both Pt and Sn doping have a similar effect on superconductivity despite being on different dopant sites, arguing against the notion that superconductivity lives predominantly in the CeIn3 planes of these materials. In addition, we shed qualitatively understanding on the doping dependence and the electronic structure with density functional theory calculations.

click the picture to download