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Observation of a common symmetry for the pseudogap and the superconducting order parameter near the surface of underdoped YBCO

G. Koren·L. Shkedy·E. Polturak
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Abstract

Measurements of the angular dependence of conductance spectra in the a-b plane of underdoped YBCO junctions are reported. At zero magnetic field the superconducting gap shows a |d+is|-like symmetry. Application of a magnetic field strongly suppresses this gap leaving only the pseudogap feature which also shows a |d+is|-like angular dependence. We thus observe the same symmetry for the superconducting gap and the pseudogap characterizing the YBCO electrodes near the interface with the barrier. An H_{c2} value of about 5T of the secondary (is) order parameter can also be deduced from our results.

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G. Koren, L. Shkedy, E. Polturak. 2003-06-24. Observation of a common symmetry for the pseudogap and the superconducting order parameter near the surface of underdoped YBCO. https://doi.org/10.1016/j.physc.2003.11.012

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