Interaction-Driven Fermi-Velocity Renormalization and Mott Criticality in Twisted WSe₂ Tetralayers

The recent observation of a tunable semimetal–to–Mott-insulator transition in twisted WSe₂ tetralayers provides an experimental realization of Dirac fermions whose interactions can be continuously tuned from weak to strong coupling. Motivated by this development, we construct a non-perturbative theoretical framework that treats the short- and long-range components of the Coulomb interaction on equal footing. We find that long-range interactions enhance the Fermi velocity while local correlations suppress it, and their competition quantitatively reproduces the experimentally observed crossover and velocity reduction at small twist angles. Twisted WSe₂ tetralayers therefore offers a direct realization of the interplay between a weak-coupling Dirac semimetal and a Gross–Neveu–type Mott insulator, providing a concrete platform to explore how competing electron–electron interactions shape quantum criticality and Fermi velocity renormalization in moiré Dirac materials.