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arXiv · 2205.15000

SuperConga: an open-source framework for mesoscopic superconductivity

P. Holmvall·N. Wall Wennerdal·M. Håkansson·P. Stadler·O. Shevtsov·T. Löfwander·M. Fogelström
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Abstract

We present SuperConga, an open-source framework for simulating equilibrium properties of unconventional and ballistic singlet superconductors, confined to two-dimensional (2D) mesoscopic grains in a perpendicular external magnetic field, at arbitrary low temperature. It aims at being both fast and easy to use, enabling research without access to a computer cluster, and visualization in real-time with OpenGL. The core is written in C++ and CUDA, exploiting the embarrassingly parallel nature of the quasiclassical theory of superconductivity by utilizing the parallel computational power of modern GPUs. The framework self-consistently computes both the superconducting order-parameter and the induced vector potential, and finds the current density, free energy, induced flux density, local density of states, as well as the magnetic moment. A user-friendly Python frontend is provided, enabling simulation parameters to be defined via intuitive configuration files, or via the command-line interface, without requiring a deep understanding of implementation details. For example, complicated geometries can be created with relative ease. The framework ships with simple tools for analyzing and visualizing the results, including an interactive plotter for spectroscopy. An overview of the theory is presented, as well as examples showcasing the framework's capabilities and ease of use. The framework is free to download from https://gitlab.com/superconga/superconga, which also links to the extensive user manual, containing even more examples, tutorials and guides.

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P. Holmvall, N. Wall Wennerdal, M. Håkansson, P. Stadler, O. Shevtsov, T. Löfwander, M. Fogelström. 2022-05-30. SuperConga: an open-source framework for mesoscopic superconductivity. https://doi.org/10.1063/5.0100324

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