s'authentifier
version française rss feed
HAL : in2p3-00184835, version 1

Fiche concise  Récupérer au format
Temperature evolution of subharmonic gap structures in MgB$_2$/Nb point-contacts
Giubileo F., Bobba F., Scarfato A., Piano S., Aprili M. et al
Dans Physica C: Superconductivity - 8th International Conference on Materials and Mechanisms of Superconductivity and High Temperature Superconductors - M2S-HTSC VIII, Dresden : Allemagne - http://hal.in2p3.fr/in2p3-00184835
Physique/Matière Condensée/Supraconductivité
Temperature evolution of subharmonic gap structures in MgB$_2$/Nb point-contacts
F. Giubileo, F. Bobba, A. Scarfato, S. Piano, M. Aprili1, 2, A.M. Cucolo
1 :  Laboratoire de Spectroscopie en Lumière Polarisée
ESPCI ParisTech
France
2 :  CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
http://www-csnsm.in2p3.fr/
CNRS : UMR8609 – IN2P3 – Université Paris XI - Paris Sud
batiments 104 et 108 - 91405 Orsay Campus
France
We have performed point-contact spectroscopy experiments on superconducting micro-constrictions between Nb tips and high quality MgB2 pellets. We measured the temperature evolution (between 4.2 K and 300 K) of the current–voltage (I–V) and of the dynamical conductance (dI/dV–V) characteristics. Above the Nb critical temperature Click to view the MathML source, the conductance of the constrictions behaves as predicted by the BTK model for S/N contacts being Nb in its normal state below Click to view the MathML source, the contacts show Josephson current and subharmonic gap structures, due to multiple Andreev reflections. These observations clearly indicate the coupling of the MgB2 3D π-band with the Nb superconducting order parameter. We found Δπ = 2.4 ± 0.2 meV for the three-dimensional gap of MgB2.

Communications avec actes
2007
Physica C: Superconductivity
internationale
460-462
B. Büchner and J. Fink
587-588
Elsevier

8th International Conference on Materials and Mechanisms of Superconductivity and High Temperature Superconductors - M2S-HTSC VIII
Dresden
Allemagne
09/07/2006
14/07/2006