title: Energy gaps in Bi(2)Sr(2)CaCu(2)O(8+δ) cuprate superconductors.
abstract: The relationship between the cuprate pseudogap (Δ(p)) and superconducting gap (Δ(s)) remains an unsolved mystery. Here, we present a temperature- and doping-dependent tunneling study of submicron Bi(2)Sr(2)CaCu(2)O(8+δ) intrinsic Josephson junctions, which provides a clear evidence that Δ(s) closes at a temperature T(c) (0) well above the superconducting transition temperature T(c) but far below the pseudogap opening temperature T*. We show that the superconducting pairing first occurs predominantly on a limited Fermi surface near the node below T(c) (0), accompanied by a Fermi arc due to the lifetime effects of quasiparticles and Cooper pairs. The arc length has a linear temperature dependence, and as temperature decreases below T(c) it reduces to zero while pairing spreads to the antinodal region of the pseudogap leading to a d-wave superconducting gap on the entire Fermi surface at lower temperatures.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics , Chinese Academy of Sciences, Beijing 100190,  China.
authors.forename: J K
authors.initials: JK
authors.lastname: Ren
authors.forename: X B
authors.initials: XB
authors.lastname: Zhu
authors.forename: H F
authors.initials: HF
authors.lastname: Yu
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.forename: H F
authors.initials: HF
authors.lastname: Yang
authors.forename: C Z
authors.initials: CZ
authors.lastname: Gu
authors.forename: N L
authors.initials: NL
authors.lastname: Wang
authors.forename: Y F
authors.initials: YF
authors.lastname: Ren
authors.forename: S P
authors.initials: SP
authors.lastname: Zhao