Current crowding effects in nanostructured superconductors

Orateur : Pr Alejandro SILHANEK (Université de Liège, Belgique)

When current stream lines are forced to depart from their rectilinear trajectory due to the presence of an obstacle, they conglomerate at the sharp bends encountered on their path. The consequent current crowding is present in normal metals as well as in superconductors and has been recently recognized as an important factor limiting the performance of superconducting single-photon detectors [1,2], leading to vortex motion rectification [3], and being a source of unwanted ratchet signal [4]. In this talk we will show that in nanostructured superconductors at low temperatures, current crowding can also trigger abrupt flux avalanches developing well defined geometrical patterns [5]. [1] J. R. Clem and K. K. Berggren, Phys. Rev. B 84, 174510 (2011) [2] J. R. Clem, Y. Mawatari, G. R. Berdiyorov, and F. M. Peeters, Phys.Rev. B 85, 144511 (2012) [3] O.-A. Adami et al. Appl. Phys. Lett. 102, 052603 (2013) [4] D. Cerbu et al. New Journal of Physics (2013) [5] M. Motta et al. e-print arXiv:1109.2532 (2011)l

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