Mesoscopic conductance fluctuations in YBa2Cu3O7-delta grain boundary junctions at low temperature
Artikel i vetenskaplig tidskrift, 2009
The magnetoconductance in YBa2Cu3O7-delta grain boundary Josephson junctions displays fluctuations at low temperatures of mesoscopic origin. The morphology of the junction suggests that transport occurs in narrow channels across the grain boundary line with a large Thouless energy. Nevertheless the measured fluctuation amplitude decreases quite slowly when increasing the voltage up to values about 20 times the Thouless energy, of the order of the nominal superconducting gap. Our findings show the coexistence of supercurrent and quasiparticle current in the junction conduction even at high nonequilibrium conditions. Model calculations confirm the reduced role of quasiparticle relaxation at temperatures up to 3 K.
Josephson effect
links
magnetic-field
magnetoresistance
josephson-junctions
superconductors
yttrium compounds
weak
thin-films
barium compounds
noise
grain boundaries
quasi-particles
transport
disordered electronic systems
fluctuations in superconductors
high-temperature superconductors
superconducting energy gap
metals
copper compounds
Författare
A. Tagliacozzo
F. Tafuri
E. Gambale
B. Jouault
D. Born
P. Lucignano
D. Stornaiuolo
Floriana Lombardi
Chalmers, Mikroteknologi och nanovetenskap, Kvantkomponentfysik
A. Barone
B. L. Altshuler
Physical Review B - Condensed Matter and Materials Physics
24699950 (ISSN) 24699969 (eISSN)
Vol. 79 2Ämneskategorier
Den kondenserade materiens fysik
DOI
10.1103/PhysRevB.79.024501