Unveiling the origin of unconventional moire ferroelectricity

Abstract

Interfacial ferroelectricity emerges in heterostructures consisting of nonpolar van der Waals (vdW) layers, greatly expanding the scope of two dimensional ferroelectrics. In particular, the unconventional moire ferroelectricity observed in bilayer graphene/boron nitride (BN) heterostructures, exhibits promising functionalities with topological current, superconductivity and synaptic responses. However, the debate about its mechanism - correlation driven charge transfer between two graphene layers - limits device reproducibility and hence large-scale production. Here by designing a single-layer graphene encapsulated by lattice-mismatched WSe2, we identify the ferroelectricity as stemming from - instead of graphene moire bands - the particular BN, where interfacial sliding ferroelectricity must play a role. With similar structures, multilayer twisted MoS2 is found to reproduce the ferroelectricity. The key is a conductive moire ferroelectric, where the screened gate and the pinned domain wall together result in unchanged electronic states, i.e. anomalous screening. The intimate connection to interfacial sliding ferroelectricity thus provides advantages of diverse choices of constituent materials and robust polarization switching while preserving the unique anomalous screening, paving the way to reproducible and reliable memory-based devices in artificial intelligence.

References in corpus (14)

• Stacking-engineered ferroelectricity in bilayer boron nitride
• Interfacial Ferroelectricity by van-der-Waals Sliding
• Recent progress in the assembly of nanodevices and van der Waals heterostructures by deterministic placement of 2D materials
• Interfacial ferroelectricity in rhombohedral-stacked bilayer transition metal dichalcogenides
• Interfacial ferroelectricity in marginally twisted 2D semiconductors
• Charge-polarized interfacial superlattices in marginally twisted hexagonal boron nitride
• Coupled Ferroelectricity and Superconductivity in Bilayer $T_d$-MoTe${}_2$
• Cumulative Polarization Coexisting with Conductivity at Interfacial Ferroelectrics
• Screw-Dislocation-Driven Growth of Two-Dimensional Few-Layer and Pyramid-Like WSe2 by Sulfur-Assisted Chemical Vapor Deposition
• Ultra-clean assembly of van der Waals heterostructures
• Direct measurement of ferroelectric polarization in a tunable semimetal
• Electrical switching of a moiré ferroelectric superconductor
• Tunable ferroelectricity in hBN intercalated twisted double-layer graphene
• Electronic ratchet effect in a moiré system: signatures of excitonic ferroelectricity

Cited by in corpus (6)

• The interplay of ferroelectricity and magneto-transport in non-magnetic moiré superlattices
• On the origin of anomalous hysteresis in graphite/boron nitride transistors
• Modular hybrid machine learning and physics-based potentials for scalable modeling of van der Waals heterostructures
• Ferroelectric-tunable quantum nonlinearity of chiral Bloch electrons in a moiré system
• Stabilization of sliding ferroelectricity through exciton condensation
• Sliding and superlubric moiré twisting ferroelectric transition in HfO2