Break-junction tunneling on MgB2

Break–junction Tunneling on Mgb 2

Tunneling data on magnesium diboride, MgB2, are reviewed with a particular focus on superconductor–insulator–superconductor (SIS) junctions formed by a break–junction method. The collective tunneling literature reveals two distinct energy scales, a large gap, ∆L ∼ 7.2 meV, close to the expected BCS value, and a small gap, ∆S ∼ 2.4 meV. The SIS break junctions show clearly that the small gap clo...

Multiband model for tunneling in MgB2 junctions

A theoretical model for quasiparticle and Josephson tunneling in multiband superconductors is developed and applied to MgB2-based junctions. The gap functions in different bands in MgB2 are obtained from an extended Eliashberg formalism, using the results of band structure calculations. The temperature and angle dependencies of MgB2 tunneling spectra and the Josephson critical current are calcu...

Break-junction tunneling measurements of the high-Tc superconductor Y1Ba2Cu3O9- delta.

Point-contact Spectroscopy of Magnesium Diboride with Different Counter-electrodes

We report on tunneling and Andreev-reflection conductance spectra of 39 K superconducting magnesium diboride, obtained with Pb and Au counter-electrodes. Two distinct steps at close to 2.7 and 7.1 meV appear in a low-resistance metallic-type Au-MgB2 junction characteristic, whereas a tunneling-like spectrum measured for the same junction, annealed by the application of dc current, exhibits only...

Reinventing the PN junction: Dimensionality Effects on Tunneling Switches

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