title: Robust dx2-y2 pairing symmetry in hole-doped cuprate superconductors.
abstract: Although initially quite controversial, it is now widely accepted that the Cooper pairs in optimally doped cuprate superconductors have predominantly dx2-y2 wave function symmetry, and the controversy has now shifted to whether the pairing symmetry changes away from optimal doping. Here we present phase-sensitive tricrystal experiments on three cuprate systems: Y(0.7)Ca(0.3)Ba(2)Cu(3)O(7-delta) (Ca-doped Y-123), La2-xSrxCuO4 (La-214), and Bi(2)Sr(2)CaCu(2)O(8+delta) (Bi-2212), with doping levels covering the underdoped, optimal, and overdoped regions. Our work implies that predominantly d x2-y2 pairing symmetry is robust over a large variation in doping.
authors.affiliation: IBM Watson Research Center, Yorktown Heights, New York, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Tsuei
authors.forename: J R
authors.initials: JR
authors.lastname: Kirtley
authors.forename: G
authors.initials: G
authors.lastname: Hammerl
authors.forename: J
authors.initials: J
authors.lastname: Mannhart
authors.forename: H
authors.initials: H
authors.lastname: Raffy
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Li