title: Towards the identification of a quantum critical line in the (p, B) phase diagram of CeCoIn5 with thermal-expansion measurements.
abstract: The low-temperature thermal expansion of CeCoIn(5) single crystals measured parallel and perpendicular to magnetic fields B oriented along the c axis yields the volume thermal-expansion coefficient β. Considerable deviations of β(T) from Fermi-liquid behavior occur already within the superconducting region of the (B, T) phase diagram and become maximal at the upper critical field B(c2)(0). However, β(T) and the Grüneisen parameter Γ are incompatible with a quantum critical point at B(c2)(0), but allow for a quantum criticality shielded by superconductivity and extending to negative pressures for B<B(c2)(0). We construct a tentative (p, B, T) phase diagram of CeCoIn(5) suggesting a quantum critical line in the (p, B) plane.
authors.affiliation: Institut für Festkörperphysik, Karlsruhe Institute of Technology, D-76021 Karlsruhe, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Zaum
authors.forename: K
authors.initials: K
authors.lastname: Grube
authors.forename: R
authors.initials: R
authors.lastname: Schäfer
authors.forename: E D
authors.initials: ED
authors.lastname: Bauer
authors.forename: J D
authors.initials: JD
authors.lastname: Thompson
authors.forename: H
authors.initials: H
authors.lastname: v Löhneysen