Phys. Rev. Lett. 71, 2134–2137 (1993)Experimental determination of the superconducting pairing state in YBCO from the phase coherence of YBCO-Pb dc SQUIDsReceived 18 June 1993; published in the issue dated 27 September 1993 We present an experiment designed to determine directly the symmetry of the pairing state in the cuprate superconductors. From the magnetic flux modulation of YBCO-Pb dc SQUIDs, we determine the spatial anisotropy of the phase of the order parameter in single crystals of YBCO. The experimental results are complicated by SQUID asymmetries and the trapping of magnetic vortices, but taken as a whole give rather strong evidence for a phase shift of π that is predicted for the dx2-y2 pairing state. This is further corroborated by single junction modulation measurements. © 1993 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.71.2134
DOI:
10.1103/PhysRevLett.71.2134
PACS:
74.50.+r, 74.20.Mn, 74.72.Bk
See AlsoComment: D. A. Wollman, D. J. Van Harlingen, and A. J. Leggett, Wollman et al. Reply, Phys. Rev. Lett. 73, 1872 (1994). Comment: Richard A. Klemm, Comment on "Experimental Determination of the Superconducting Pairing State in YBCO from the Phase Coherence of YBCO-Pb dc SQUIDs", Phys. Rev. Lett. 73, 1871 (1994). |
