Regensburg 2019 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 57: Superconductivity: Properties and Electronic Structure

TT 57.6: Vortrag

Donnerstag, 4. April 2019, 16:15–16:30, H7

Phase slip lines in few-layer NbSe₂ superconducting devices — •Nicola Paradiso, Anh-Tuan Nguyen, Karl Enzo Kloß, and Christoph Strunk — University of Regensburg

The advent of van der Waals superconductors made it possible to study 2D superconductivity in a fascinating clean regime, so far rarely studied in conventional films. In this work we show that, owing to their low level of disorder and atomically sharp edges, few-layer monocrystalline NbSe₂ flakes do not switch directly to the normal phase under large current bias. Instead, a sequential nucleation of phase slip lines (PSLs) is observed in all the samples under study. We investigate the dynamic of PSL nucleation in a Au-NbSe₂ point contact, where the temperature and bias dependence of the PSL-induced conductance step is quantitatively described by the simple model of Skocpol, Beasley and Tinkham. In plain devices, the PSL pattern is sample dependent. However, we demonstrate that it is possible to induce an artificial PSL nucleation site by mechanically stressing a flake across its whole width.