Researchers from Oxford’s Centre for Applied Superconductivity (CfAS) in Oxford Physics have uncovered the impressive properties of a novel superconductor, marking it out as the best of its kind with huge technological potential. The novel material in question, CaKFe4As4, was first synthesised only a couple of years ago both in Japan and Ames Laboratory, USA. Remarkably, its critical current density in single crystals was found to exceed that of all known iron-based superconductors, with a value of around 107 A/cm2. This is over ten times larger than that of current state-of-the-art ‘BaK-122’ superconductors. A high critical current density is important for industrial applications, as it broadens the possibilities for superconducting cables and is crucial for producing high magnetic field superconducting magnets, such as those found in MRI scanners. Their measurements showed in addition that CaKFe4As4 has a relatively high critical temperature of 35 K and a large critical field of exceeding 80 T. The CfAS group plans to now devote its efforts to developing CaKFe4As4 in both wire and powder forms, as this material has the potential to overturn existing applied superconductor research and provide a new and exciting class of superconducting technologies. The results of this research have been recently published in Phys. Rev. Materials 2, 074802 (2018) and they are also posted on the open access archive.