Abstract
We have fabricated tunnel junctions between chemically etched single crystals of YBa2Cu3O7- and evaporated metal counterelectrodes that exhibit reproducible characteristics. Above the bulk critical temperature of YBa2Cu3O7-, Tc, the conductance as a function of voltage, G(V), has a linear dependence on voltage and some asymmetry. Below Tc, additional structure associated with the superconducting state appears in G(V). At TTc there is a reproducible finite zero-bias conductance, which suggests that there are states at the Fermi energy in superconducting YBa2Cu3O7-. Junctions with Pb, Sn, Bi, Sb, PbBi, and Au counterelectrodes all show qualitatively similar behavior.
Original language | English |
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Pages (from-to) | 11986-11996 |
Number of pages | 11 |
Journal | Physical Review B |
Volume | 44 |
Issue number | 21 |
DOIs | |
State | Published - 1991 |