The problem of dissipation in superconductors is associated with variations in
time of the order parameter. In disordered wires, finite resistivity arises from the
generation of phase slip centers where the order parameter oscillates between
its maximum value and zero. These are manifested as discrete jumps in the
current-voltage (I-V) curve. This phenomenon is well-studied in quasi-1D
superconductors, and possibilities for utilizing it to design quantum devices have
also been explored. We will discuss about the occurrence of a related
phenomenon in superconducting films away from the 1D limit. In the case of
quasi-1D systems, phase slips appear at weak points when the bias current
exceeds the critical current. For a 2D film, this presents a different scenario since
a weak point is insufficient to impede supercurrent flow along the entire cross
section. We will present results of experiments to study this question focusing on
conductance measurements of superconducting films. We have mapped the
transport properties in the intermediate bias regime, which reveals current
carrying steady states that are not accessible in simple current-biased
measurements. The results show the existence of a complex distribution of
nonequilibrium states which can be tracked on the current-voltage plane. We
will discuss about the fundamental aspects of this phenomenon and its interest
in the design of non-linear superconducting networks.
Wann? | 26.08.2025 13:30 |
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Wo? | PER 08 2.73 Chemin du Musée 3, 1700 Fribourg |
Vortragende | Dr. Shamahis Sengupta
Université Paris-Saclay, France Invited by group Bernhard |
Kontakt | Département de Physique Dr Subhrangsu SARKAR subhrangsu.sarkar@unifr.ch |