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Evidence for Surface Andreev Bound states in Cuprate Superconductors from Penetration Depth Measurements

A. Carrington·F. Manzano·R. Prozorov·R. W. Giannetta·N. Kameda·T. Tamegai
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Abstract

Tunneling and theoretical studies have suggested that Andreev bound states form at certain surfaces of unconventional superconductors. Through studies of the temperature and field dependence of the in-plane magnetic penetration depth lambda_ab at low temperature, we have found strong evidence for the presence of these states in clean single crystal YBCO and BSCCO. Crystals cut to expose a [110] interface show a strong upturn in lambda_ab at around 7K, when the field is oriented so that the supercurrents flow around this surface. In YBCO this upturn is completely suppressed by a field of ~0.1 T.

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A. Carrington, F. Manzano, R. Prozorov, R. W. Giannetta, N. Kameda, T. Tamegai. 2000-11-10. Evidence for Surface Andreev Bound states in Cuprate Superconductors from Penetration Depth Measurements. https://doi.org/10.1103/physrevlett.86.1074

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