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

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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Cited by in corpus (2)

• Observation of McMillan-Rowell like oscillations in underdoped YBCO junctions oriented along the node of the d-wave order parameter
• Magnetoresistance of Junctions made of Underdoped YBCO Separated by a Ga-doped YBCO Barrier