Superconducting energy gap of underdoped and overdoped Bi2Sr2CaCu2O8

Abstract The tunneling conductance was measured for a natural-barrier planar tunneling junction of underdoped and overdoped Bi 2 Sr 2 CaCu 2 O 8 . The temperature dependence of the separation between the gap edge peaks suggests that the amplitude of superconducting gap becomes zero at the superconducting critical temperature.