Quantum Phase Transitions in Graphene Coupled to a Twisted WSe ₂ Moiré Ferroelectricity

Abstract

Abstract Sublattice symmetry in graphene governs its Dirac semimetal behavior, where electrons exhibit linear dispersion, limiting its potential for technological applications. Here, moiré ferroelectricity in twisted WSe 2 ( t ‐WSe 2 ) is exploited to break graphene's sublattice symmetry, inducing a metal‐to‐insulator transition (MIT) near room temperature. The periodic polarization domains in t ‐WSe 2 imprint an electrostatic potential onto graphene, breaking its sublattice symmetry and leading to the emergence of a local Dirac point, as observed in the transfer characteristics of a t ‐WSe 2 /graphene field‐effect transistor. Temperature‐dependent transport measurements reveal multiple MIT points at relatively high temperatures, attributed to the room‐temperature ferroelectric polarization in t ‐WSe 2 . Furthermore, A distinct metallic phases is identified exhibiting T 2 and linear‐ T dependent longitudinal resistance under electrostatic doping, indicative of Fermi‐liquid and non‐Fermi‐liquid metallic behavior, respectively. Finally, finite‐size scaling analysis of R xx near the MIT points indicates continuous quantum phase transitions near room temperature, establishing moiré ferroelectricity as a pathway for engineering quantum electronic phases of monolayer graphene at ambient conditions.