Title :
Optically induced depinning and Josephson coupling in bulk Bi-Sr-Ca-Cu-O
Author_Institution :
Dept. of Electr. & Comput. Eng., Colorado Univ., Boulder, CO, USA
fDate :
3/1/1991 12:00:00 AM
Abstract :
Bridgelike constrictions were fabricated from polycrystalline bulk Bi-Sr-Ca-Cu-O (BSCCO), and their resistive transition was investigated as a function of temperature. DC current, magnetic field, and optical irradiation. The data are well described by a network of highly damped Josephson junctions. Evidence for optically induced depinning of vortices is presented. A threshold value was found for the product of current density and flux density, above which the resistivity increased linearly with applied magnetic field. This behavior is attributed to flux flow, and for conventional superconductors it is described by the Bardeen-Stephen relationship. It is shown that many electrical characteristics predicted by this model resemble flux creep
Keywords :
Josephson effect; bismuth compounds; calcium compounds; critical current density (superconductivity); flux creep; flux flow; flux pinning; high-temperature superconductors; radiation effects; strontium compounds; superconducting transition temperature; Bardeen-Stephen relationship; Bi-Sr-Ca-Cu-O; DC current; Josephson coupling; applied magnetic field; bridgelike constrictions; current density; electrical characteristics; flux creep; flux density; flux flow; high temperature superconductivity; highly damped Josephson junctions; optical irradiation; optically induced depinning; polycrystalline bulk; resistive transition; resistivity; temperature dependence; threshold value; Bismuth compounds; Conductivity; Current density; Electric variables; Josephson junctions; Magnetic fields; Optical coupling; Optical vortices; Superconducting transition temperature; Superconductivity;
Journal_Title :
Magnetics, IEEE Transactions on
