Asymmetric current-voltage characteristics in type-II superconductors

• Published in: Physical review. B, Condensed matter Vol. 49; no. 13; pp. 9244 - 9247
• Main Authors: Jiang, X, Connolly, PJ, Hagen, SJ, Lobb, CJ
• Format: Journal Article
• Language: English
• Published: United States 01-04-1994
• Subjects: 360104 > Metals & Alloys > Physical Properties; ALLOYS; BISMUTH ALLOYS; CERIUM COMPOUNDS; CERIUM OXIDES; CHALCOGENIDES; COPPER COMPOUNDS; CRITICAL CURRENT; CUPRATES; CURRENTS; ELECTRIC CURRENTS; EPITAXY; LEAD ALLOYS; LEAD BASE ALLOYS; MAGNETIC FLUX; MAGNETIC PROPERTIES; MATERIALS SCIENCE; MIXED STATE; NEODYMIUM COMPOUNDS; NEODYMIUM OXIDES; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; RARE EARTH COMPOUNDS; SUPERCONDUCTING FILMS; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE; TEMPERATURE RANGE 0000-0013 K; TRANSITION ELEMENT COMPOUNDS 360207 > Ceramics, Cermets, & Refractories > Superconducting Properties > (1992-)
• ISSN: 0163-1829; 1095-3795
• DOI: 10.1103/PhysRevB.49.9244

We report asymmetric current-voltage characteristics in superconducting films in a parallel magnetic field. The critical current, [ital I][sub [ital c]], is found to differ by as much as 30% for negative and positive currents, and beyond [ital I][sub [ital c]], the magnitude of the voltage is also different for positive and negative currents, [vert bar][ital V](+[ital I])[vert bar][ne][vert bar][ital V]([minus][ital I])[vert bar]. The critical current difference [vert bar][ital I][sub [ital c]+][vert bar][minus][vert bar][ital I][sub [ital c][minus]][vert bar] has complicated behavior, changing sign as temperature and magnetic field are varied. We propose a model based on the Bean-Livingston surface barrier and inhomogeneous bulk pinning that accounts for all observed behavior.