Oscillations of magnetization and conductivity in anisotropic Fulde-Ferrell-Larkin-Ovchinnikov superconductors

François Konschelle (1) , Jérôme Cayssol (1) , Alexandre I. Buzdin (1, 2)

1 CPMOH - Centre de physique moléculaire optique et hertzienne
2 IUF - Institut universitaire de France

We derive the fluctuational magnetization and the paraconductivity of Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconductors in their normal state. The FFLO superconducting fluctuations induce oscillations of the magnetization between diamagnetism and unusual paramagnetism which originates from the competition between paramagnetic and orbital effects. We also predict a strong anisotropy of the paraconductivity when the FFLO transition is approached in contrast with the case of a uniform BCS state. Finally building a Ginzburg-Levanyuk argument, we demonstrate that these fluctuation effects can be safely treated within the Gaussian approximation since the critical fluctuations are proeminent only within an experimentally inaccessible temperature interval.

Domaines: Supraconductivité [cond-mat.supr-con]

François Konschelle, Jérôme Cayssol, Alexandre I. Buzdin. Oscillations of magnetization and conductivity in anisotropic Fulde-Ferrell-Larkin-Ovchinnikov superconductors. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2009, 79 (22), pp.224526 (1-11). ⟨10.1103/PhysRevB.79.224526⟩. ⟨hal-00361192v2⟩