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Robust dx2-y2 pairing symmetry in high-temperature superconductors

C. C. Tsuei·J. R. Kirtley·G. Hammerl·J. Mannhart·H. Raffy·Z. Z. Li
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Abstract

Although initially quite controversial, it has been widely accepted that the Cooper pairs in optimally doped cuprate superconductors have predominantly dx2-y2 wavefunction symmetry. The controversy has now shifted to whether the high-Tc pairing symmetry changes away from optimal doping. Here we present phase-sensitive tricrystal experiments on three cuprate systems: Y0.7Ca0.3Ba2Cu3O7-x (Ca-doped Y-123), La2-xSrxCuO4 (La-214) and Bi2Sr2CaCu2O8+x (Bi-2212),with doping levels covering the underdoped, optimal and overdoped regions. Our work implies that time-reversal invariant, predominantly dx2-y2 pairing symmetry is robust over a large variation in doping, and underscores the important role of on-site Coulomb repulsion in the making of high-temperature superconductivity.

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C. C. Tsuei, J. R. Kirtley, G. Hammerl, J. Mannhart, H. Raffy, Z. Z. Li. 2004-02-26. Robust dx2-y2 pairing symmetry in high-temperature superconductors. https://doi.org/10.1103/physrevlett.93.187004

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