[en] 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 paths. The consequent current crowding is present in normal metals as well as in superconductors and has been, since long ago, identified as a key player in electromigration phenomena leading to failure in integrated circuit interconnects while might also be at the origin of local ablation in planar plasmonic structures. More recently, current crowding has been recognized as an important factor limiting the performance of superconducting single-photon detectors, leading to flux quanta motion rectification, or being a source of unwanted ratchet signal and depletion of surface barriers for magnetic flux penetration. In this talk, we will also show that in nanostructured superconductors at low temperatures, current crowding can trigger abrupt flux avalanches developing well defined geometrical patterns. Our experimental findings are backed up to the finest details, by simulations based on a phenomenological thermomagnetic model which, in turn, can be used to predict such complex structures and, given its reliability, allows one to estimate physical variables of more difficult experimental access, such as the local values of temperature and electric field.
Disciplines :
Physics
Author, co-author :
Silhanek, Alejandro ; Université de Liège > Département de physique > Physique expérimentale des matériaux nanostructurés
Language :
English
Title :
Electric current crowding in nanostructured conductors
Publication date :
24 May 2015
Event name :
XXXVIII National Meeting on Condensed MatterPhysics