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Nonmonotonic d_{x^2-y^2} Superconducting Order Parameter in Nd_{2-x}Ce_xCuO_4

G. Blumberg·A. Koitzsch·A. Gozar·B. S. Dennis·C. A. Kendziora·P. Fournier·R. L. Greene
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Abstract

Low energy polarized electronic Raman scattering of the electron doped superconductor Nd_1.85Ce_0.15CuO_4 (T_c=22 K) has revealed a nonmonotonic d_{x^2-y^2} superconducting order parameter. It has a maximum gap of 4.4 k_BT_c at Fermi surface intersections with antiferromagnetic Brillouin zone (the ``hot spots'') and a smaller gap of 3.3 k_BT_c at fermionic Brillouin zone boundaries. The gap enhancement in the vicinity of the ``hot spots'' emphasizes role of antiferromagnetic fluctuations and similarity in the origin of superconductivity for electron- and hole-doped cuprates.

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G. Blumberg, A. Koitzsch, A. Gozar, B. S. Dennis, C. A. Kendziora, P. Fournier, R. L. Greene. 2002-01-29. Nonmonotonic d_{x^2-y^2} Superconducting Order Parameter in Nd_{2-x}Ce_xCuO_4. https://doi.org/10.1103/physrevlett.88.107002

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