We show that the doping-controlled superconductor-insulator transition (SIT) in a high critical temperature cuprate system (Bi2Sr2-xLaxCaCu2O8+delta) exhibits a fundamentally different behavior than is expected from conventional SIT. At the critical doping, the sheet resistance seems to diverge in the zero temperature limit. Above the critical doping, the transport is universally scaled by a two-component conductance model. Below, it continuously evolves from weakly to strongly insulating behavior. The two-component conductance model suggests that a collective electronic phase separation mechanism may be responsible for this unconventional SIT behavior.
@article{arxiv.cond-mat/0509521,
title = {Doping Controlled Superconductor-Insulator Transition in Bi2Sr2-xLaxCaCu2O8+delta},
author = {Seongshik Oh and Trevis A. Crane and D. J. Van Harlingen and J. N. Eckstein},
journal= {arXiv preprint arXiv:cond-mat/0509521},
year = {2007}
}
Comments
21 pages, 5 figures, abstract changed. Introduction and conclusion expanded. Slight changes in the main text. Accepted to PRL