Scanning Tunneling Spectroscopy of the superconducting proximity effect in a diluted ferromagnetic alloy

L. Cretinon (1) , A. K. Gupta (1) , H. Sellier (2, 3, 4) , F. Lefloch (2, 5, 6) , M. Faure (7) , Alexandre I. Buzdin (7, 8) , Hervé Courtois (9)

1 CRTBT - Centre de Recherches sur les Très Basses Températures
2 DRFMC - Département de Recherche Fondamentale sur la Matière Condensée
3 TUDELFT / NANOSCIENCE - Physics of NanoElectronics
4 KI-NANO - Kavli Institute of Nanosciences [Delft]
5 SPSMS - UMR 9001 - Service de Physique Statistique, Magnétisme et Supraconductivité
6 LaTEQS - Laboratoire de Transport Electronique Quantique et Supraconductivité
7 CPMOH - Centre de physique moléculaire optique et hertzienne
8 IUF - Institut universitaire de France
9 CP

We studied the proximity effect between a superconductor (Nb) and a diluted ferromagnetic alloy (CuNi) in a bilayer geometry. We measured the local density of states on top of the ferromagnetic layer, which thickness varies on each sample, with a very low temperature Scanning Tunneling Microscope. The measured spectra display a very high homogeneity. The analysis of the experimental data shows the need to take into account an additional scattering mechanism. By including in the Usadel equations the effect of the spin relaxation in the ferromagnetic alloy, we obtain a good description of the experimental data.

Domaines: Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]; Supraconductivité [cond-mat.supr-con]

L. Cretinon, A. K. Gupta, H. Sellier, F. Lefloch, M. Faure, et al.. Scanning Tunneling Spectroscopy of the superconducting proximity effect in a diluted ferromagnetic alloy. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2005, 72 (2), pp.024511 (1-6). ⟨hal-00219755⟩