Layer-dependent electromechanical response in twisted graphene moiré superlattices
arXiv:2406.11442 · doi:10.1021/acsnano.4c01794
Abstract
The coupling of mechanical deformation and electrical stimuli at the nanoscale has been a subject of intense investigation in the realm of materials science. Recently, twisted van der Waals (vdW) materials have emerged as a platform to explore exotic quantum states. These states are intimately tied to the formation of moiré superlattices, which can be visualized directly exploiting the electromechanical response. However, the origin of the response, even in twisted bilayer graphene (tBLG), remains unsettled. Here, employing lateral piezoresponse force microscopy (LPFM), we investigate the electromechanical responses of marginally twisted graphene moiré superlattices with different layer thicknesses. We observe distinct LPFM amplitudes and spatial profiles in tBLG and twisted monolayer-bilayer graphene (tMBG), exhibiting effective in-plane piezoelectric coefficients of 0.05 pm/V and 0.35 pm/V, respectively. Force tuning experiments further underscore a marked divergence in their responses. The contrasting behaviors suggest different electromechanical couplings in tBLG and tMBG. In tBLG, the response near the domain walls is attributed to the flexoelectric effect, while in tMBG, the behaviors can be comprehended within the context of piezoelectric effect. Our results not only provide insights to electromechanical and corporative effects in twisted vdW materials with different stacking symmetries, but may also show their potential for engineering them at the nanoscale.
References in corpus (28)
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
- Moire bands in twisted double-layer graphene
- Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
- Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
- Intrinsic quantized anomalous Hall effect in a moiré heterostructure
- Graphene Bilayers with a Twist
- Interfacial Ferroelectricity by van-der-Waals Sliding
- Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene
- Spin-polarized Correlated Insulator and Superconductor in Twisted Double Bilayer Graphene
- Cascade of electronic transitions in magic-angle twisted bilayer graphene
- Cascade of Phase Transitions and Dirac Revivals in Magic Angle Graphene
- Nematicity and Competing Orders in Superconducting Magic-Angle Graphene
- Band Structure of Twisted Bilayer Graphene: Emergent Symmetries, Commensurate Approximants and Wannier Obstructions
- Electrical switching of magnetic order in an orbital Chern insulator
- Strain fields in twisted bilayer graphene
- One-Dimensional Moiré Excitons in Transition-Metal Dichalcogenide Heterobilayers
- Topologically Protected Helical States in Minimally Twisted Bilayer Graphene
- Tunable correlation-driven symmetry breaking in twisted double bilayer graphene
- Commensurate-incommensurate phase transition in bilayer graphene
- Heterostrain engineering on twisted graphene bilayer around the first magic angle
- Networks of ABA and ABC stacked graphene on mica observed by scanning tunneling microscopy
- Bichiral structure of feroelectric domain wall driven by flexoelectricity
- Unraveling intrinsic flexoelectricity in twisted double bilayer graphene
- Engineering of Atomic-Scale Flexoelectricity at Grain Boundaries
- Electrical switching of a moiré ferroelectric superconductor
- Dislocations in stacking and commensurate-incommensurate phase transition in bilayer graphene and hexagonal boron nitride
- Symmetry breaking and anomalous conductivity in a double moiré superlattice