High-Tc superconductivity research in the University of Science and Technology of China

To celebrate the 50th anniversary of the founding of the University of Science and Technology of China, a brief review is presented of recent research on high-Tc superconductivity there. The search for new high-Tc materials and experimental research on the mechanism of high-Tc superconductivity led to our discovery of the Fe-based arsenide superconductor——SmO1-xFxFeAs, which is the first non-copper-oxide superconductor with a transition temperature beyond the McMillan limit (39 K), while the highest transition temperature in this system can reach 55 K. A variety of superconducting single crystals including Nd2-xCexCuO4, NaxCoO2 and CuxTiSe2 have been successfully grown. To understand the mechanism of high-Tc superconductivity we have systematically studied the electronic transport of the SmO1-xFxFeAs system and proposed a corresponding electronic phase diagram. Abnormal thermal hysteresis and spin-charge coupling have been found in electron-type high-Tc superconductors. In the NaxCoO2 system the magnetic structure of the small magnetic moment in the charge ordered state has been clarified. The relationship between charge density waves and superconductivity in the CuxTiSe2 system has also been studied.