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MgB2 tunnel junctions and 19 K low-noise dc superconducting quantum interference devices

Y. Zhang·D. Kinion·J. Chen·D. G. Hinks·G. W. Crabtree·John Clarke
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Abstract

Point contact junctions made from two pieces of MgB2 can be adjusted to exhibit either superconductor-insulator-superconductor (SIS) or superconductor-normal metal-superconductor (SNS) current-voltage characteristics. The SIS characteristics are in good agreement with the standard tunneling model for s-wave superconductors, and yield an energy gap of (2.02 +/- 0.08) meV. The SNS characteristics are in good agreement with the predictions of the resistively-shunted junction model. DC Superconducting QUantum Interference Devices made from two SNS junctions yield magnetic field noise as low as 35 fT/Hz^{1/2} at 19 K.

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Y. Zhang, D. Kinion, J. Chen, D. G. Hinks, G. W. Crabtree, John Clarke. 2001-07-23. MgB2 tunnel junctions and 19 K low-noise dc superconducting quantum interference devices. https://doi.org/10.1063/1.1424465

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