DOI: 10.1209/epl/i2002-00570-7


Europhys. Lett., 57 (2) , p. 260 (2002)

Intrinsic percolative superconductivity in heavily overdoped high-temperature superconductors

H. H. Wen, S. L. Li, Z. W. Zhao, Z. Y. Liu, H. P. Yang, D. N. Zheng and Z. X. Zhao

National Laboratory for Superconductivity, Institute of Physics and Center for Condensed Matter Physics, Chinese Academy of Sciences P.O. Box 603, Beijing 100080, PRC

hhwen@aphy.iphy.ac.cn

(Received 28 June 2001; accepted in final form 1 November 2001)

Abstract
Magnetic measurements on heavily overdoped _{2-x x 4}, , , _1-x ( _x) and single crystals reveal a new type of magnetization hysteresis loops characterized by the vanishing of the usual central peak near zero field. Since this effect has been observed in various systems with very different structural details, it probably reflects a generic behavior for all high-temperature superconductors. This easy penetration of magnetic flux can be understood in the picture of percolative superconductivity due to the inhomogeneous electronic state in heavily overdoped regime.

PACS
74.25.Bt - Thermodynamic properties.
74.20.Mn - Nonconventional mechanisms (spin fluctuations, polarons and bipolarons, resonating valence bond model, anyon mechanism, marginal Fermi liquid, Luttinger liquid, etc.).
74.40.+k - Fluctuations (noise, chaos, nonequilibrium superconductivity, localization, etc.).


© EDP Sciences 2002