Naslov
Vortex motion noise in amorphous Nb0.7Ge0.3 microbridges

Autori
Babić, Dinko ; Strunk, Christoph ; Nusbaumer, Thomas ; Schoenenberger, Christian ; Suergers, Christoph

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Proceedings of the XXIII International Conference on Low Temperature Physics / - Hiroshima, 2002

Skup
XXIII International Conference on Low Temperature Physics

Mjesto i datum
Hiroshima, Japan, 15.08.2002. - 21.08.2002

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
Vortex motion; noise

Sažetak
We report high-resolution measurements of voltage (V) noise in the mixed state of micrometre-sized thin films of amorphous Nb0.7Ge0.3, which is a good representative of weak-pinning superconductors. There is a remarkable difference between the noise below and above the irreversibility field B//irr. Below B//irr, in the presence of measurable pinning, the noise at small applied currents resembles shot noise, and in the regime of flux flow at larger currents decreases with increasing voltage due to a progressive ordering of the vortex motion. At magnetic fields B between B//irr and the upper critical field B//c2 flux flow is present already at vanishingly small currents. In this regime the noise scales with (1-B/B//c2})^2 V^2 and has a frequency (f) spectrum of 1/f type. We interpret this noise in terms of the properties of strongly driven depinned vortex systems at high vortex density.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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