Designer Moiré Quantum Materials Enabled by Freestanding Oxide Membranes in Twisted and Hybrid Bilayers.

With the increasing demand for emergent functionalities in next-generation electronic devices, materials research has shifted from conventional materials discovery toward structural reconstruction and interface engineering. In this regime, the discovery of moiré superlattices has established twistronics as a powerful platform for generating emergent phenomena through twist-induced modulations of atomic registry and interfacial coupling. While most twist-engineered systems have been confined to van der Waals materials, extending them to strongly correlated complex oxides represents a challenging yet promising frontier. Recent developments in freestanding oxide membranes have enabled this transition by eliminating substrate-imposed epitaxial constraints and allowing deterministic stacking and twisting of crystalline oxide thin films. Experiments have established structural moiré superlattices, polar textures, and registry-dependent charge disproportionation. In contrast, flat bands, charge ordering, and tunable magnetic interactions remain primarily theoretical predictions requiring direct experimental verification. Hybrid oxide-two-dimensional (2D) heterostructures further combine correlated oxides degree of freedom with the tunable electronic and optical properties of 2D materials, opening new opportunities for unconventional moiré physics. In this review, we summarize the recent advances in oxide twistronics, spanning freestanding oxide membranes, twisted oxide bilayers, and hybrid oxide-2D moiré heterostructures, while highlighting future direction for engineering emergent quantum phases and next-generation multifunctional device architectures.