Title :
Direct observation of vortex dynamics in two-dimensional Josephson-junction arrays
Author :
Doderer, T. ; Lachenmann, S.G. ; Huebener, R.P. ; Booi, P.A.A. ; Benz, S.P.
Author_Institution :
Lehrstuhl Experimentalphys. II, Tubingen Univ., Germany
fDate :
6/1/1995 12:00:00 AM
Abstract :
Spatially resolved images of the dynamic states of current-biased overdamped two-dimensional arrays of Nb/AlO/sub x//Nb Josephson junctions were obtained using low-temperature scanning electron microscopy. We present two-dimensional imaging results describing various vortex dynamic regimes in zero applied magnetic field. The nucleation of current-induced vortices at the array boundaries and their subsequent motion into the array interior are observed for bias currents slightly above the array critical current. With increasing bias current, vortex-vortex interaction becomes important. Discussions on the coherent microwave radiation emission are presented.<>
Keywords :
Josephson effect; aluminium compounds; critical currents; flux flow; niobium; scanning electron microscopy; superconducting device testing; superconducting junction devices; Nb-AlO-Nb; Nb/AlO/sub x//Nb Josephson junctions; coherent microwave radiation emission; critical current; current-biased overdamped two-dimensional arrays; current-induced vortex nucleation; low-temperature scanning electron microscopy; spatially resolved images; two-dimensional Josephson-junction arrays; two-dimensional imaging; vortex dynamics; vortex-vortex interaction; zero applied magnetic field; Coupling circuits; Critical current; Image resolution; Josephson junctions; Niobium; Oscillators; Resistors; Resonance; Scanning electron microscopy; Voltage;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
