Charge transport in normal metal-magnesiumdiboride junctions

Abstract

The influence of the multiband nature of superconductivity in MgB 2 on the charge transport properties of MgB 2 tunnel junctions and normal metal-MgB 2 heterostructures has been theoretically modeled and experimentally explored. The conductance as function of barrier height and angle is calculated. Planar c-axis tunnel junctions are realized in which two gaps are resolved in the tunnel spectrum. For junctions with additional conductance in the direction of the crystallographic a-b plane we observe a sharp resonance that can possibly be attributed to a Leggett mode. © 2005 Elsevier Ltd. All rights reserved.