Current-induced self-organisation of mixed superconducting states

Small-angle neutron scattering is used in combination with transport measurements to investigate the current-induced effects on the morphology of the intermediate mixed state domains in the inter-type superconductor niobium. We report the robust self-organisation of the vortex lattice domains to elongated parallel stripes perpendicular to the applied current in a steady-state. The experimental results for the formation of the superstructure are supported by theoretical calculations, which highlight important details of the vortex matter evolution. The investigation demonstrates a mechanism of a spontaneous pattern formation that is closely related to the universal physics governing the intermediate mixed state in low-κ superconductors.

Uniformly Frustrated XY Model: Strengthening of the Vortex Lattice by Intrinsic Disorder

In superconducting films, the role of intrinsic disorder is typically to compete with superconductivity by fragmenting the global phase coherence and lowering the superfluid density. Nonetheless, when a transverse magnetic field is applied to the system and an Abrikosov vortex lattice form, the presence of disorder can actually strengthen the superconducting state against thermal fluctuations. By means of Monte Carlo simulations on the uniformly frustrated XY model in two dimensions, we show that while for weak pinning the superconducting critical temperature Tc increases with the applied field H, for strong enough pinning, the experimental decreasing dependence between Tc and H is recovered with a resulting more robust vortex lattice.

Typhoon: A vortex-lattice code for assessing dynamic stability characteristics of hydrofoil crafts

In this paper an open-source implementation of the vortex-lattice method to perform a dynamic stability analysis for hydrofoil crafts is discussed. The difference with existing vortex-lattice codes is the addition of a free-surface boundary condition which is needed to analyse surface piercing foils. This code, called Typhoon, can be used to perform a dynamic stability analysis (DSA) on hydrofoil vessels. The goal of this code is to have an easy-to-use and cheap alternative to compare different designs in early design stages. This paper gives a brief background to all the concepts used, followed by a short theoretical explanation of the vortex-lattice method. The second part of this paper focuses on a practical example of how this code can be used on an example.