title: Superconductivity in CeCoIn5-xSnx: veil over an ordered state or novel quantum critical point?
abstract: Measurements of specific heat and electrical resistivity in magnetic fields up to 9 T along [001] and temperatures down to 50 mK of Sn-substituted CeCoIn5 are reported. The maximal -ln(T) divergence of the specific heat at the upper critical field Hc2 down to the lowest temperature characteristic of non-Fermi-liquid systems at the quantum critical point (QCP), the universal scaling of the Sommerfeld coefficient, and agreement of the data with spin-fluctuation theory provide strong evidence for quantum criticality at Hc2 for all x< or =0.12 in CeCoIn5-xSnx. These results indicate the "accidental" coincidence of the QCP located near Hc2 in pure CeCoIn5, in actuality, constitute a novel quantum critical point associated with unconventional superconductivity.
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Bauer
authors.forename: C
authors.initials: C
authors.lastname: Capan
authors.forename: F
authors.initials: F
authors.lastname: Ronning
authors.forename: R
authors.initials: R
authors.lastname: Movshovich
authors.forename: J D
authors.initials: JD
authors.lastname: Thompson
authors.forename: J L
authors.initials: JL
authors.lastname: Sarrao