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.
Categories: cond-mat.supr-con