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Experimental test for subdominant superconducting phases with complex order parameters in cuprate grain boundary junctions

W. K. Neils·D. J. Van Harlingen
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Abstract

We propose and implement a direct experimental test for subdominant superconducting phases with broken time-reversal symmetry in d-wave superconductors. The critical current of 45-degree asymmetric grain boundary junctions are shown to be extremely sensitive to the predicted onset of a complex order parameter at (110)-surfaces and near magnetic impurities. Measurements in YBCO and Ni-doped YBCO junctions indicate that the symmetry at the surface is consistent with pure d-wave at all temperatures, putting limits on the magnitude and chiral domain structure of any subdominant symmetry component.

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W. K. Neils, D. J. Van Harlingen. 2001-05-20. Experimental test for subdominant superconducting phases with complex order parameters in cuprate grain boundary junctions. https://doi.org/10.1103/physrevlett.88.047001

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