Polar projections for big data analysis in applied superconductivity

E F Talantsev,R C Mataira

doi:10.1063/1.5038040

Abstract

There is a growing problem to represent and analyse large experimental datasets in many emerging fields of science aside of traditional big data-based disciplines, i.e., elementary particles, genetics/genomics and geoscience. One of these emerging fields is applied superconductivity where recently a large, regularly up-dated, public database of critical currents of commercial superconductors was established. The size, dimensionality and resolution of this data makes current methods of display and analysis inadequate. As is often the case in physics and materials science, when dealing with any anisotropic properties, one measures the effects of rotations around a low symmetry axis, this is also the case in critical current measurements as found in applied superconductivity. In this paper we propose the use of polar projected images to map these much larger data sets into useful visualizations for analysis. Where we suggest the radial coordinate and the colour represent amplitudes of two measured parameters, and sample rotation angle is naturally mapped to the polar coordinate. We demonstrate the advantage of this projection for analysing, otherwise unwieldy large, critical current datasets, and naturally recover previously used empirical relations.

Highlights

Dissipation-free electric current is one of the most fascinating and practically important properties of superconductors
All high-temperature superconductors (HTS), which are in demand for use in future large-scale projects,[15] are strongly anisotropic, where the anisotropy is largely dependent on the manufacture’s technology
We propose a new way to represent large experimental datasets measured in experiments, when one or several parameters of anisotropic material are measured while sample rotates around low symmetry axis

Summary

Introduction

Dissipation-free electric current is one of the most fascinating and practically important properties of superconductors. Maximal dissipation-free current is designated as the critical current, Ic. The standard approach to deduce critical currents from experimental I-V curve measurements is to fit the latter to a power law:[1,2,3,4,5,6,7]. Is another value which is in use to scale Jc(B,T ) at high magnetic fields.[1,15,16] All high-temperature superconductors (HTS), which are in demand for use in future large-scale projects,[15] are strongly anisotropic, where the anisotropy is largely dependent on the manufacture’s technology. That for many practical applications, the primary experimental geometry

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Conclusion