Advances in Understanding the Mechanisms of Moiré Ferroelectricity

Moiré ferroelectricity provides a platform for regulating interfacial polarization in two-dimensional van der Waals materials through local stacking, lattice reconstruction and mesoscale domain formation. In these systems, polarization is governed by interlayer symmetry breaking, charge redistribution, orbital hybridization, lattice relaxation, strain gradients and electronic screening. This review summarizes recent progress in graphene/hBN, twisted hBN, rhombohedral transition metal dichalcogenides and marginally twisted transition metal dichalcogenides, and discusses how these systems have advanced the understanding of moiré-scale polarization. This mechanistic understanding has evolved together with characterization methods, from electrical hysteresis and local electrostatic mapping to multimodal analysis of stacking structures, domain-wall dynamics and polarization vector fields. The review then analyzes polarization origins, including stacking-dependent interfacial dipoles, reconstructed polar domains, electrostatic imprinting and electronically assisted polarization. It also discusses polarization switching and domain-wall dynamics, emphasizing local stacking conversion, domain-wall migration, dislocation-network rearrangement, soliton-network evolution and pinning-depinning processes. Furthermore, it clarifies the distinction between ordinary periodic polar-domain patterns and topological polar textures, which require vector-field reconstruction, in-plane polarization rotation, winding or chirality, and structural correlation with domain walls or saddle-point regions. Finally, this review outlines perspectives on operando characterization under device-relevant conditions, ultrafast switching, multi-field control and deterministic domain-wall engineering.