Direct Transition from Bose Glass to Normal State in the (K,Ba)BiO3 Superconductor

Thierry Klein (1, 2) , C. Marcenat (3, 4) , S. Blanchard (1) , J. Marcus (1) , C. Bourbonnais (4) , R. Brusetti (5) , C. J. van Der Beek (6) , M. Konczykowski (6)

1 LEPES - Laboratoire d'Etudes des Propriétés Electroniques des Solides
2 IUF - Institut universitaire de France
3 SPSMS - UMR 9001 - Service de Physique Statistique, Magnétisme et Supraconductivité
4 UdeS - Université de Sherbrooke
5 CRTBT - Centre de Recherches sur les Très Basses Températures
6 LSI - Laboratoire des Solides Irradiés - Irradiated Solids Laboratory

The introduction of columnar defects in K; Ba BiO3 single crystals shifts both the irreversibility and thermodynamic transition lines, respectively, deduced from ac susceptibility (and/or transport) and specific heat measurements, upwards. This shift can be attributed to the defect-induced decrease of the difference ( F) between the free energies in the superconducting and the normal states, assuming that the position of the superconducting transition is given by the condition j Fj kBT= 3. This criterion also perfectly reproduces the influence of the angle between the tracks and the external field. This result suggests that no vortex liquid phase exists in this system.

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

Thierry Klein, C. Marcenat, S. Blanchard, J. Marcus, C. Bourbonnais, et al.. Direct Transition from Bose Glass to Normal State in the (K,Ba)BiO3 Superconductor. Physical Review Letters, 2004, 92, pp.037005. ⟨10.1103/PhysRevLett.92.037005⟩. ⟨hal-00959094⟩