Longitudinal Proximity Effects in Superconducting Transition-Edge Sensors

TitleLongitudinal Proximity Effects in Superconducting Transition-Edge Sensors
Publication TypeJournal Article
Year of Publication2010
AuthorsSadleir JE, Smith SJ, Bandler SR, Chervenak JA, Clem JR
Journal TitlePhysical Review Letters
Date Published01/29
ISBN Number0031-9007
Accession NumberISI:000274336600045
Keywordsdetectors, noise, sandwiches, supercurrents, x-ray microcalorimeters

We have found experimentally that the critical current of a square thin-film superconducting transition-edge sensor (TES) depends exponentially upon the side length L and the square root of the temperature T, a behavior that has a natural theoretical explanation in terms of longitudinal proximity effects if the TES is regarded as a weak link between superconducting leads. As a consequence, the effective transition temperature T-c of the TES is current dependent and at fixed current scales as 1/L-2. We have also found that the critical current can show clear Fraunhofer-like oscillations in an applied magnetic field, similar to those found in Josephson junctions. We have observed the longitudinal proximity effect in these devices over extraordinarily long lengths up to 290 mu m, 1450 times the mean-free path.

URL<Go to ISI>://000274336600045
DOIDoi 10.1103/Physrevlett.104.047003