oa High-Tc superconductivity: from basic research to useful applications

Background: Superconductivity is the complete loss of electric resistance in some elements and compounds cooled below a transition temperature (Tc). Since its discovery more than 100 years ago, this phenomenon has enriched basic science in ways that nobody could have foreseen. Moreover, superconductors have been used in various applications like power transmission, high magnetic field generation, levitated high-speed trains (MAGLEV), and magnetic resonance imaging (MRI). In a county, like Qatar, seeking to find alternative renewable energy sources, superconductors can be greatly useful in connecting the electric power generated from the renewable energy sources (solar and wind power) with superconducting devices (especially cables) to fulfill the energy saving and sustainability objectives. Objectives and methods: The effective use of superconductors in applications requires a better understanding of the basic phenomena of high-Tc superconductivity. For this purpose, several techniques are used especially photoemission spectroscopy which is considered as the most powerful tool to directly investigate the electronic structure of solids including superconductors. This technique is based on the photoelectric effect where various light sources like synchrotron radiation, lasers and others may be used. We have been using photoemission spectroscopy to investigate the electronic structure of newly discovered superconductors known as iron pnictides since their discovery in Japan in 2008. We have used several facilities like the Institute for Solid State Physics at the University of Tokyo in Japan, Photon Factory in Japan, Hiroshima Synchrotron Radiation Center at Hiroshima University in Japan, and Stanford Synchrotron Radiation Lightsource at Stanford University in USA. Our work was published in refereed scientific journals and presented at many international conferences worldwide and has had important implications on this field from the very early stage. Results and conclusions: In this paper, I will present an introduction about superconductivity and highlight on its various possible applications especially in Qatar. Also I will present an overview of our research on newly discovered iron pnictide superconductors using photoemission spectroscopy and how our results led to a better understanding of high-Tc superconductivity in these compounds.