Origin of metal-insulator transitions in the parent compounds of ruthenium-pnictide superconductors

The authors explore here the origin of metal-to-insulator transition (MIT) in the parent compounds of recently discovered ruthenium pnictide superconductors. Using various first-principles calculations, such as density functional and dynamical mean-field theories, they rule out electronic correlation and Fermi surface nesting as the drivers for MIT. Instead, they suggest electron-phonon coupling as the most likely mechanism to induce the transition from an insulating monoclinic to a metallic orthorhombic phase. They propose ultrafast light-induced novel two-step MIT in these systems,which calls for further investigation.