Related papers: Geometry-induced reduction of the critical current…
In this paper we calculate the critical currents in thin superconducting strips with sharp right-angle turns, 180-degree turnarounds, and more complicated geometries, where all the line widths are much smaller than the Pearl length $\Lambda…
We demonstrate experimentally that the critical current in superconducting NbTiN wires is dependent on their geometrical shape, due to current-crowding effects. Geometric patterns such as 90 degree corners and sudden expansions of wire…
The current density in a superconductor with turnarounds or constrictions is non-uniform due to a geometrical current crowding effect. This effect reduces the critical current in the superconducting structure compared to a straight segment…
The critical current of a thin superconducting strip of width $W$ much larger than the Ginzburg-Landau coherence length $\xi$ but much smaller than the Pearl length $\Lambda = 2 \lambda^2/d$ is maximized when the strip is straight with…
We performed comparative experimental investigation of superconducting NbN nanowires which were prepared by means of positive-and negative electron-beam lithography with the same positive tone Poly-methyl-methacrylate (PMMA) resist. We show…
We have experimentally compared the critical current, dark count rate and photo-response of 100nm wide superconducting nanowires with different bend designs. Enhanced critical current for nanowires with optimally rounded bends, and thus…
We show that avoiding bends in a current-carrying superconducting nanowire enhances the probability for low energy photons to be detected and that this enhancement is entirely due to the increase in the experimentally achievable critical…
We study experimentally the low temperature resistance of superconducting nanowires connected to normal metal reservoirs. We find that a substantial fraction of the nanowires is resistive, down to the lowest temperature measured, indicative…
In recent experiments with a superconducting nanosized Pb bridge formed between a scanning tunneling microscope tip and a substrate, superconductivity has been detected at magnetic fields, which are few times larger than the third (surface)…
Coherent quantum phase slips are expected to lead to a blockade of dc conduction in sufficiently narrow superconducting nanowires below a certain critical voltage. We present measurements of NbN nanowires in which not only is a critical…
We measured the critical temperatures and critical switching and retrapping currents of wide and narrow thin-film quasi-one-dimensional superconducting aluminum structures of the same thickness in zero magnetic field. For the first time, we…
Superconducting fluctuations in long and narrow strips made from ultrathin NbN films, have been investigated. For large bias currents close to the critical current fluctuations led to localized, temporary transitions into the normal…
Sn is a well-known classical superconductor on the border between type I and type II with critical temperature of 3.722K and critical field of 0.031T. We show by means of specific heat and electric magneto-transport data that its critical…
Vortex dynamics is strongly connected with the mechanisms responsible for the photon detection of superconducting devices. Indeed, the local suppression of superconductivity by photon absorption may trigger vortex nucleation and motion…
Using a microscopic approach, we revisit the problem of superconducting critical temperature change in the presence of twin boundaries. We show that both critical temperature enhancement and suppression can come purely from geometric…
Key questions for any superconductor include: what is its maximum dissipation-free electrical current (its `critical current') and can this be used to extract fundamental thermodynamic parameters? Present models focus on depinning of…
The gate-voltage-induced suppression of critical currents in metallic superconductors observed recently [De Simoni et al., Nat. Nanotechnol. 13, 802 (2018)] has raised crucial questions regarding the nature and mechanism of the electric…
We have recently proposed a theoretical model for superconductors endowed with two distinct superconducting phases, described by two scalar order parameters which condensate at different critical temperatures. On analyzing the magnetic…
We consider the critical temperature for superconductivity, defined via the linear BCS equation. We prove that at weak coupling the critical temperature for a sample confined to a quadrant in two dimensions is strictly larger than the one…
We derive and analyze the low-energy theory of superconductivity in carbon nanotube ropes. A rope is modelled as an array of ballistic metallic nanotubes, taking into account phonon-mediated plus Coulomb interactions, and Josephson coupling…