title: Reentrant superconductivity driven by quantum tricritical fluctuations in URhGe: evidence from ^{59}Co NMR in URh_{0.9}Co_{0.1}Ge.
abstract: Our measurements of the ^{59}Co NMR spin-spin relaxation in URh_{0.9}Co_{0.1}Ge reveal a divergence of electronic spin fluctuations in the vicinity of the field-induced quantum critical point at H_{R}≈13  T, around which reentrant superconductivity (RSC) occurs in the ferromagnetic heavy fermion compound URhGe. We map out the strength of spin fluctuations in the (H_{b},H_{c}) plane of magnetic field components and show that critical fluctuations develop in the same limited region near the field H_{R} as that where RSC is observed. This strongly suggests these quantum fluctuations as the pairing glue responsible for the RSC. The fluctuations observed are characteristic of a tricritical point, followed by a phase bifurcation toward quantum critical end points.
authors.affiliation: ASRC, Japan Atomic Energy Agency Tokai, Ibaraki 319-1195, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tokunaga
authors.affiliation: INAC/SPSMS, CEA-Grenoble/UJF, 38054 Grenoble, France.|IMR, Tohoku University, Ibaraki 311-1313, Japan.
authors.forename: D
authors.initials: D
authors.lastname: Aoki
authors.affiliation: LNCMI, UPR 3228, CNRS-UJF-UPS-INSA, 38042 Grenoble, France.
authors.forename: H
authors.initials: H
authors.lastname: Mayaffre
authors.affiliation: LNCMI, UPR 3228, CNRS-UJF-UPS-INSA, 38042 Grenoble, France.
authors.forename: S
authors.initials: S
authors.lastname: Krämer
authors.affiliation: LNCMI, UPR 3228, CNRS-UJF-UPS-INSA, 38042 Grenoble, France.
authors.forename: M-H
authors.initials: MH
authors.lastname: Julien
authors.affiliation: LNCMI, UPR 3228, CNRS-UJF-UPS-INSA, 38042 Grenoble, France.
authors.forename: C
authors.initials: C
authors.lastname: Berthier
authors.affiliation: LNCMI, UPR 3228, CNRS-UJF-UPS-INSA, 38042 Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Horvatić
authors.affiliation: ASRC, Japan Atomic Energy Agency Tokai, Ibaraki 319-1195, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sakai
authors.affiliation: ASRC, Japan Atomic Energy Agency Tokai, Ibaraki 319-1195, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kambe
authors.affiliation: INAC/SPSMS, CEA-Grenoble/UJF, 38054 Grenoble, France.|Department of Physics, Okayama University, Okayama 700-8530, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Araki