title: Coexistence and interplay of superconductivity and ferromagnetism in URhGe.
abstract: As ferromagnetism and superconductivity are usually considered to be antagonistic, the discovery of their coexistence in UGe(2), URhGe, UIr and UCoGe has attracted a lot of interest. The mechanism to explain such a state has, however, not yet been fully elucidated. In these compounds superconductivity may be unconventional: Cooper pairs could be formed by electrons with parallel spins and magnetic fluctuations might be involved in the pairing mechanism. URhGe becomes ferromagnetic below a Curie temperature of 9.5 K, with a spontaneous moment aligned to the c-axis. For temperatures below 260 mK and fields lower than 2 T, superconductivity was first observed in 2001. Recently, we discovered a second pocket of superconductivity. This new pocket of superconductivity appears at higher fields applied close to the b-axis, enveloping a sudden magnetic moment rotation transition at H(R) = 12 T. Detailed studies of the field induced metamagnetic transition and superconductivity are presented. The possibility that magnetic fluctuations emerging from a quantum critical point provide the pairing mechanism for superconductivity is discussed.
authors.affiliation: Département de Physique de la Matière Condensée, Université de Genève, quai Ernest-Ansermet 24, CH1211, Genève 4, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Lévy
authors.forename: I
authors.initials: I
authors.lastname: Sheikin
authors.forename: B
authors.initials: B
authors.lastname: Grenier
authors.forename: C
authors.initials: C
authors.lastname: Marcenat
authors.forename: A
authors.initials: A
authors.lastname: Huxley