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Jeudi 25 Fevrier 2016 14h
Amphi Holweck, Esc C,
1ème etage
Titre:U – based Ferromagnetic Superconductors
In this talk we will present recent results obtained on U based ferromagnetic superconductors in the laboratory IMAPEC in CEA Grenoble. Up to now four U based compounds are know which show the microscopic coexistence of ferromagnetism and superconductivity. We will compare the pressure – temperature – magnetic field phase diagrams of UGe2, URhGe, and UCoGe and discuss the ferromagnetic quantum phase transition and Fermi surface properties as function of magnetic field and high pressure. In the orthorhombic systems URhGe and UCoGe the application of a magnetic field along the hard magnetization axis induces an enhancement of the superconductivity which is connected to the enhancement of the ferromagnetic fluctuations under magnetic field and the strong Ising character of the magnetic fluctuations. The unusual superconducting upper critical field of UCoGe and its anisotropy will be discussed as function of pressure.
Work performed in collaborations with D. Aoki, S. Araki, G. Bastien, D. Braithwaite, A. Gourgout, A. Pourret, J.P. Brison, B. Wu, V. Taufour, J. Flouquet