Routes to High-Temperature Superconductivity: A Lesson from FeSe/SrTiO3

Raising the superconducting transition temperature to a point where applications are practical is one of the most important challenges in science. In this review, we aim at gaining insights on the T-c controlling factors for a particular high-temperature superconductor family-the FeSe-based superconductors. In particular, we discuss the mechanisms by which the Cooper pairing temperature is enhanced from (8 similar to) K in bulk FeSe to similar to 80 K in the interface between an atomic layer of FeSe and SrTiO3. This includes the experimental hints and the theoretical simulation of the involved mechanisms. We end by applying these insights to suggest some possible high-temperature superconducting systems.