Development of Ultrafast Nonvolatile Memory Based on Sliding Ferroelectricity in Moiré Polar Homostructures

Twisted stacks of van der Waals (vdW) crystals can form moiré superlattices with polar domains whose dipoles are antiferroelectrically aligned and controllable by applied electric fields [1]. Sliding ferroelectricity arises from nm-scale interlayer sliding in vdW materials, coupling in-plane atomic displacement to out-of-plane polarization switching [2]. This mechanism has been demonstrated in bilayer hexagonal boron nitride and semiconducting transition metal dichalcogenides, where polarization reversal can occur with minimal energy dissipation [3]. Recent Department of War investments through the Multidisciplinary University Research Initiative (MURI) have demonstrated advances in twisted two-dimensional heterostructures into atomically thin twistronic memory cell prototypes with potential advantages in speed, endurance, energy efficiency, and scalability [2, 3]. The advancement and prototype development requires a combined multidisciplinary expertise in the design, fabrication, measurement, and modeling of lattice dynamics in twisted moiré van der Waals structures, as well as charge transport and optoelectronics in van der Waals materials. The technical approach should exploit the atomically thin nature, low defect density, and strong in-plane bonding of vdW materials to develop sliding ferroelectric nonvolatile memory devices designed to outperform current memory technologies in speed, endurance, and scalability. Engineered nanoscale polar domains in moiré superlattices will serve as nonvolatile memory cells based on local ferroelectricity. To demonstrate the electrical and optical readouts in the designed nonvolatile memory devices, the proposal should leverage the scalability and controllability features of well-established systems, such as Graphene field-effect transistors and transition-metal-dichalcogenide-based field-effect transistors.