ISSN:
1077-3118
Source:
AIP Digital Archive
Topics:
Physics
Notes:
One important potential application of high-temperature superconductors is for tunnel junctions, especially hysteretic Josephson junctions. Unfortunately, tunnel junctions of oxide superconductors with a useful Tc(approximately-greater-than)20 K have exhibited nonideal I(V) characteristics with a normalized zero-bias conductance, σs/σn(0), of 15–50%. We present data on point-contact junctions of Ba1−xKxBiO3 which clearly demonstrate that these problems are not intrinsic. Using a normal-metal counterelectrode, σs/σn(0) was 〈1% and σs/σn(V) agreed with the BCS theory by including only thermal smearing. Using a superconducting Nb counterelectrode, the I(V) showed very sharp features with evidence of a proximity effect, and σs/σn(0) was 〈0.2%. These results prove that there is no fundamental limitation for tunnel junctions using this HTS material, and one can anticipate operation of devices with two Ba1−xKxBiO3 electrodes at 15–20 K.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.104172
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