Europhys. Lett.
Volume 60, Number 2, October 2002
Page(s) 295 - 301
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 01 October 2002
DOI: 10.1209/epl/i2002-00350-5

Europhys. Lett., 60 (2) , pp. 295-301 (2002)

Increase of the critical current at the liquid-helium lambda point in superconducting perforated multilayers

S. L. Prischepa1, 2, L. V. Mercaldo1, C. Attanasio1, M. Salvato1, L. Maritato1, 3 and S. Barbanera4

1  Dipartimento di Fisica "E. R. Caianiello" and INFM Università degli Studi di Salerno - Baronissi (Salerno), I-84081, Italy
2  State University of Informatics and Radio Electronics P.Brovka street 6, Minsk 220013, Belarus
3  Dipartimento di Fisica, Università degli Studi di Cagliari Cagliari, I-09042, Italy
4  IESS-CNR - Via Cineto Romano 42, Roma, I-00100, Italy

(Received 28 February 2002; accepted in final form 26 July 2002)

Pinning properties of $\chem{Nb/CuMn}$ multilayers with regular array of antidots have been studied at different temperatures in perpendicular magnetic field. The presence of antidots causes a sudden increase (jump) of the critical current at the liquid-helium lambda point ( T=2.18 $\un{K}$). The jump value is a function of magnetic field and sample anisotropy. The hypothesis of liquid helium wetting the antidots below 2.18 $\un{K}$, and then inducing a larger pinning efficiency, is put forward.

74.60.Ge - Flux pinning, flux creep, and flux-line lattice dynamics.
74.80.Dm - Superconducting layer structures: superlattices, heterojunctions, and multilayers.

© EDP Sciences 2002