Andreev Bound States at the Onset of Phase Coherence in Bi(2)Sr(2)CaCu(2)O(8).
A new technique of planar tunneling spectroscopy has been developed to access the in-plane density of states of optimally doped Bi(2)Sr(2)CaCu(2)O(8) single crystals. The low energy spectrum is observed to depend on crystallographic orientation. When tunnel current is injected nominally along the Cu-Cu bond direction, a zero-bias conductance peak is observed to appear simultaneously with the onset of bulk superconductivity. These data demonstrate the existence of surface-induced states in this system and confirm the d-wave symmetry of the superconducting order parameter.
Aubin
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Loomis Laboratory of Physics and the Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA. Herve.Aubin@espci.fr
Greene
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Jian
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Hinks
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