title: Field-induced quantum critical point in CeCoIn5.
abstract: The resistivity of the heavy-fermion superconductor CeCoIn5 was measured as a function of temperature, down to 25 mK and in magnetic fields of up to 16 T applied perpendicular to the basal plane. With increasing field, we observe a suppression of the non-Fermi liquid behavior, rho approximately T, and the development of a Fermi liquid state, with its characteristic rho=rho(0)+AT2 dependence. The field dependence of the T2 coefficient shows critical behavior with an exponent of 1.37. This is evidence for a field-induced quantum critical point (QCP), occurring at a critical field which coincides, within experimental accuracy, with the superconducting critical field H(c2). We discuss the relation of this field-tuned QCP to a change in the magnetic state, seen as a change in magnetoresistance from positive to negative, at a crossover line that has a common border with the superconducting region below approximately 1 K.
authors.affiliation: Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7. paglione@physics.utoronto.ca
authors.forename: Johnpierre
authors.initials: J
authors.lastname: Paglione
authors.forename: M A
authors.initials: MA
authors.lastname: Tanatar
authors.forename: D G
authors.initials: DG
authors.lastname: Hawthorn
authors.forename: Etienne
authors.initials: E
authors.lastname: Boaknin
authors.forename: R W
authors.initials: RW
authors.lastname: Hill
authors.forename: F
authors.initials: F
authors.lastname: Ronning
authors.forename: M
authors.initials: M
authors.lastname: Sutherland
authors.forename: Louis
authors.initials: L
authors.lastname: Taillefer
authors.forename: C
authors.initials: C
authors.lastname: Petrovic
authors.forename: P C
authors.initials: PC
authors.lastname: Canfield