Tunneling into Current-Carrying Surface States of High-Tc Superconductors

Author(s): M. Fogelström, D. Rainer and J. A. Sauls
Comments: 4 pages Postscript
Published in Physical Review Letters, 79, 281-284, (1997) [DOI]

Theoretical results for the ab-plane tunneling conductance in the d-wave model for high Tc superconductors are presented. The d-wave model predicts surface bound states below the maximum gap. A sub-dominant order parameter, stabilized by the surface, leads to a splitting of the zero-bias conductance peak (ZBCP) in zero external field and to spontaneous surface currents. In a magnetic field screening currents shift the quasiparticle bound state spectrum and lead to a voltage splitting of the ZBCP that is linear in H at low fields, and saturates at a pairbreaking critical field of order Hc* = 3 T. Comparisons with recent experimental results on Cu/YBCO junctions are presented.

Paper: [arXiv] [PDF] [PS]

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