Electrical Transport Measurements on Layered La(O,F)BiS2 under Extremely High Pressure

Layered La(O,F)BiS2 exhibits drastic enhancements of the superconducting transition temperature (T-c) under high pressure among the BiS2-based superconducting family. However, the high-pressure application beyond a high-T-c phase of the monoclinic structure has not been conducted. In this study, the electrical transport properties in La(O,F)BiS2 single crystal are measured under high pressures up to 83 GPa. An insulating phase without superconductivity is observed under a higher-pressure region above 16 GPa. Moreover, the sample exhibits metallicity and superconductivity above 60 GPa. The newly observed hidden semiconducting phase and reentrant superconductivity have attracted much attention in BiS2-based compounds.