Volume 80, Number 6, December 2007
Article Number 67004
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
Published online 07 November 2007
EPL, 80 (2007) 67004
DOI: 10.1209/0295-5075/80/67004

FFLO state in thin superconducting films

A. Buzdin1, Y. Matsuda2, 3 and T. Shibauchi2

1  Institut Universitaire de France and Université Bordeaux I, CPMOH, UMR 5798 - 33405 Talence, France
2  Department of Physics, Kyoto University - Sakyo-ku, Kyoto 606-8502, Japan
3  Institute for Solid State Physics, University of Tokyo - Kashiwa, Chiba 277-8581, Japan

received 5 September 2007; accepted in final form 17 October 2007; published December 2007
published online 7 November 2007

We present the analysis of the inhomogeneous Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) superconducting state in thin superconducting films in the parallel magnetic field. For the tetragonal crystal symmetry (relevant to CeCoIn5 -the most probable candidate for the FFLO state formation) we predict a very peculiar in-plane angular dependence of the FFLO critical field due to the orbital effect. In the uniform superconducting state the critical field should be isotropic. The magnetic field pins also the direction of the FFLO modulation permitting thus to study the critical-current anisotropy. Our calculations reveal a strong critical-current anisotropy in the FFLO state in sharp contrast with the usual superconducting state. The predicted characteristic anisotropies of the critical field and critical current may provide an unambiguous probe of the FFLO phase formation.

74.45.+c - Proximity effects; Andreev effect; SN and SNS junctions.
74.78.Fk - Multilayers, superlattices, heterostructures.
74.81.-g - Inhomogeneous superconductors and superconducting systems.

© Europhysics Letters Association 2007