Title :
In-plane magnetic field dependence of intrinsic Josephson junctions in Tl-Ba-Ca-Cu-O thin films
Author :
Warburton, P.A. ; Chana, O.S. ; Kuzhakhmetov, A.R. ; Hyland, D.M.C. ; Dew-Hughes, D. ; Grovenor, C.R.M. ; Koval, Y. ; Müller, P.
Author_Institution :
Dept. of Electron. Eng., King´´s Coll., London, UK
fDate :
3/1/2001 12:00:00 AM
Abstract :
We have fabricated intrinsic Josephson bridges using Tl-Ba-Ca-Cu-O thin films grown on vicinal lanthanum aluminate substrates. Measurements of the lock-in transition allow us align a magnetic field of up to 4 T with the copper oxide planes to better than 0.3°. This allows us to study the dynamics of Josephson fluxons in the films. For fields above 1.4 T and at low currents we observe Josephson flux creep. Above a field-dependent threshold current we observe free flow of the fluxons with a flux-flow resistance which is proportional to field. The fluxons reach a field-independent velocity before the jump to the quasiparticle branch occurs. Our results suggest that the development of a sub-mm-wave oscillator using these bridges will require sub-micron patterning
Keywords :
Josephson effect; barium compounds; calcium compounds; flux creep; flux flow; high-temperature superconductors; quasiparticles; superconducting thin films; thallium compounds; 1.4 to 4 T; Tl-Ba-Ca-Cu-O; Tl-Ba-Ca-Cu-O thin film; flux creep; flux flow; fluxon dynamics; intrinsic Josephson junction; lanthanum aluminate substrate; lock-in transition; magnetic field; quasiparticle velocity; sub-MM-wave oscillator; superconducting bridge; threshold current; Bridges; Copper; Creep; Josephson junctions; Lanthanum; Magnetic field measurement; Magnetic fields; Magnetic films; Threshold current; Transistors;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
