Magnetism, electronic coherence, superconductivity, and surface state*

Local inhomogeneity has a great impact on the electronic band structure and magnetic properties of correlated quantum materials. We apply neutron spectroscopy, together with spatially-resolved chemical and electrical analysis, to a topological superconductor candidate, FeTe_1-xSe_x. Combining with photoemission spectroscopy, we obtain detailed physical and chemical information, which points to an underlying connection among magnetism, electronic coherence, superconductivity, and the topological surface state.