Quantum and topological phases in iron chalcogenides

Iron chalcogenide FeTexSe1-x offers a remarkable playground in case studying correlated physics and macroscopic quantum states. However, due to its rich physics and multi-orbital nature, it is challenging to disentangle the intricate interrelation between different phases and figure out the main controlling factors of its superconductivity and normal state. In this talk, we present examples that go beyond the traditional chemical substitution experimental method and tackle the problem from several new angles: 1. we demonstrate the compositional control for potential topological superconductivity by combining microscale spatial-resolved spectroscopy and transport measurements, based on which we construct detailed quantum and topological phase diagrams over 2,000 data sets [1]; 2. we apply ionic liquid gating to simplify the complex effect of chemical substitution and pin down the power-law index of the recently discovered scaling relationship [2] between the slope of T-linear resistivity and superconducting transition temperature; 3. by altering film thicknesses and surface conditions, we find evidence for interconnected quantum percolation in the normal and superconducting states.