First-principles study of the insulator-metal transition in CrGeTe₃ under pressure

Recently, CrGeTe₃ has been experimentally reported to undergo an isostructural insulator-to-metal transition under pressure with unusually large enhancement of the magnetic transition temperature. Here, we study the insulator-metal transition and the electronic structures of the insulating and metallic phases using first-principles calculations based on a combination of density functional theory and embedded dynamical mean field theory (eDMFT). We find that our eDMFT calculations properly reproduce the charge-transfer insulator state at ambient condition and the transition to the metallic phase under pressure, where the inclusion of spin-orbit coupling is essential. We further investigate the character of the metallic states in the paramagnetic and ferromagnetic regimes and clarify the effect of electron correlation in the metallic ferromagnetic states. Our results shed important light on the insulator-metal transition and the resulting correlated phases in CrGeTe₃under pressure.