Intrinsic percolative superconductivity in heavily overdoped high-temperature superconductors

Abstract

Magnetic measurements on heavily overdoped $La_{2-x}Sr_xCuO_4$,\n$Tl_2Ba_2CuO_6$, $Bi_2Sr_2CuO_6$ and $Bi_2Sr_2CaCu_2O_8$ single crystals reveal\na new type magnetization hysteresis loops characterized by the vanishing of\nusual central peak near zero field. Since this effect has been observed in\nvarious systems with very different structural details, it reflects probably a\ngeneric behavior for all high temperature superconductors. This easy\npenetration of magnetic flux can be understood in the picture of percolative\nsuperconductivity due to the inhomogeneous electronic state in heavily\noverdoped regime.\n