Nanoscale ferroelectric programming of van der Waals heterostructures

Abstract

The ability to create superlattices in van der Waals (vdW) heterostructures via moiré interference heralded a new era in the science and technology of two-dimensional materials. Through precise control of the twist angle, flat bands and strongly correlated phases have been engineered. The precise twisting of vdW layers is in some sense a bottom-up approach--a single parameter can dial in a wide range of periodic structures. Here, we describe a top-down approach to engineering nanoscale potentials in vdW layers using a buried programmable ferroelectric layer. Ultra-low-voltage electron beam lithography (ULV-EBL) is used to program ferroelectric domains in a ferroelectric Al_{1-x}B_{x}N thin film through a graphene/hexagonal boron nitride (hBN) heterostructure that is transferred on top. We demonstrate ferroelectric field effects by creating a lateral p-n junction, and demonstrate spatial resolution down to 35 nm, limited by the resolution of our scanned probe characterization methods. This innovative, resist-free patterning method is predicted to achieve 10 nm resolution and enable arbitrary programming of vdW layers, opening a pathway to create new phases that are inaccessible by moiré techniques. The ability to "paint" different phases of matter on a single vdW "canvas" provides a wealth of new electronic and photonic functionalities.

9 pages, 4 figures and supplemental material

References in corpus (19)

• Boron nitride substrates for high-quality graphene electronics
• Chiral tunneling and the Klein paradox in graphene
• Observation of Moiré Excitons in WSe2/WS2 Heterostructure Superlattices
• Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
• Graphene Bilayers with a Twist
• Selective transmission of Dirac electrons and ballistic magnetoresistance of \textit{n-p} junctions in graphene
• Observation of Fractionally Quantized Anomalous Hall Effect
• Moiré heterostructures as a condensed matter quantum simulator
• Quantum anomalous Hall effect from intertwined moiré bands
• Effect of disorder on a graphene p-n junction
• Anisotropic band flattening in graphene with 1D superlattices
• Topological and stacked flat bands in bilayer graphene with a superlattice potential
• Strongly adhesive dry transfer technique for van der Waals heterostructure
• Ultra-sharp lateral $p\text{-}n$ junctions in modulation-doped graphene
• Nanoscale electrostatic control in ultra clean van der Waals heterostructures by local anodic oxidation of graphite gates
• Signature of Correlated Insulator in Electric Field Controlled Superlattice
• Ultrahigh energy storage density in epitaxial AlN/ScN superlattices
• Transport Anisotropy in One-dimensional Graphene Superlattice in the High Kronig-Penney Potential Limit
• Nanoscale control of LaAlO3/SrTiO3 metal-insulator transition using ultra-low-voltage electron-beam lithography