title: Pressure dependence of the Fulde-Ferrell-Larkin-Ovchinnikov state in CeCoIn5.
abstract: Pressure studies of the thermodynamics of CeCoIn5 under magnetic fields H parallel to c and H parallel to ab have been made up to P = 1.34 GPa. We recorded the signature of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state for all pressures when H parallel to ab. Also remarkably, the FFLO regime suddenly expands for P = 1.34 GPa. With the help of a microscopic theory for d-wave superconductivity, we have extracted the gyromagnetic ratio g and the Fermi velocities nu(a) and nu(c). Our study is the first evidence for the existence of the FFLO state away from the influence of the antiferromagnetic fluctuations. We find a close parallel between the T-P phase diagram of CeCoIn5 and the T-x phase diagram of the high-Tc cuprates, where x is the hole concentration.
authors.affiliation: Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Strasse 40, 01187 Dresden, Germany.
authors.forename: C F
authors.initials: CF
authors.lastname: Miclea
authors.forename: M
authors.initials: M
authors.lastname: Nicklas
authors.forename: D
authors.initials: D
authors.lastname: Parker
authors.forename: K
authors.initials: K
authors.lastname: Maki
authors.forename: J L
authors.initials: JL
authors.lastname: Sarrao
authors.forename: J D
authors.initials: JD
authors.lastname: Thompson
authors.forename: G
authors.initials: G
authors.lastname: Sparn
authors.forename: F
authors.initials: F
authors.lastname: Steglich