Phys.org February 14, 2023
Recent experiments in moiré transition metal dichalcogenide materials have reported the observation of a continuous bandwidth-tuned transition from a metal to a paramagnetic Mott insulator at a fixed filling of one electron per moiré unit cell. The electrical transport measurements reveal several puzzling features that are seemingly at odds with the theoretical expectations of an interaction-induced, but disorder-free, bandwidth-tuned metal-insulator transition. A team of researchers in the US (Cornell University, MIT) included the effects of long-wavelength inhomogeneities, building on the results for a continuous metal-insulator transition at fixed filling in the clean limit. They examined the effects of mesoscale inhomogeneities near the critical point on transport using the framework of random resistor networks, highlighting the salient differences from a simple percolation-based picture… read more. TECHNICAL ARTICLE
A simplified phase diagram for a continuous MIT showing a metallic… Credit: Phys. Rev. Lett. 130, 066301, 9 February 2023