Doping controlled superconductor-insulator transition in Bi2Sr2-xLaxCaCu2O8+delta.
We show that the doping-controlled superconductor-insulator transition (SIT) in a high critical temperature cuprate system (Bi(2)Sr(2-x)La(x)CaCu(2)O(8+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.
Oh
Seongshik
S
Department of Physics, University of Illinois, Urbana, 61801, USA. soh4@uiuc.edu
Crane
Trevis A
TA
Van Harlingen
D J
DJ
Eckstein
J N
JN