Robust structural superlubricity of twisted graphene bilayer and domain walls between commensurate moiré pattern domains from first-principles calculations

Abstract

Twisted graphene layers exhibit extremely low friction for relative sliding. Nevertheless, previous studies suggest that the area contribution to friction for commensurate moiré systems is finite and might restrict macroscopic superlubricity for large layer overlaps. In this paper, we investigate the potential energy surface (PES) for relative displacement of the layers forming moiré patterns (2,1) and (3,1) by accurate density functional theory calculations using the vdW-DF3 functional. The amplitudes of PES corrugations on the order of 0.4 and 0.03 $\mu$eV per atom of one layer, respectively, are obtained. The account of structural relaxation doubles this value for the (2,1) pattern, while causing only minimal changes for the (3,1) pattern. We show that different from aligned graphene layers, for moiré patterns, PES minima and maxima can switch their positions upon changing the interlayer distance. The PES shape is closely described by the first spatial Fourier harmonics both with and without account of structural relaxation. A barrier for relative rotation of the layers to an incommensurate state that can make superlubricity robust is estimated based on the approximated PES. We also derive a set of measurable physical properties related to interlayer interaction including shear mode frequency, shear modulus and static friction force. Furthermore, we predict that it should be possible to observe domain walls separating commensurate domains, each comprising a large number of moiré pattern unit cells, and provide estimates of their characteristics.

13 pages, 6 figures

References in corpus (19)

• Quantum ESPRESSO toward the exascale
• van der Waals forces in density functional theory: The vdW-DF method
• Origin of band gaps in graphene on hexagonal boron nitride
• Next-generation non-local van der Waals density functional
• Commensurate-incommensurate phase transition in bilayer graphene
• Superlubric to stick-slip sliding of incommensurate graphene flakes on graphite
• Atomistic simulations of the sliding friction of graphene flakes
• Moiré metrology of energy landscapes in van der Waals heterostructures
• Commensurate-incommensurate phase transition and a network of domain walls in bilayer graphene with a biaxially stretched layer
• Stacking in incommensurate graphene/hexagonal-boron-nitride heterostructures based on ab initio study of interlayer interaction
• Atomic-scale defects restricting structural superlubricity: Ab initio study study on the example of the twisted graphene bilayer
• Twirling and spontaneous symmetry breaking of domain wall networks in lattice-reconstructed heterostructures of 2D materials
• Energetics and Structure of Domain Wall Networks in Minimally Twisted Bilayer Graphene under Strain
• Two phases with different domain wall networks and a reentrant phase transition in bilayer graphene under strain
• Bulk-scale synthesis of randomly stacked graphene with high crystallinity
• Universal description of potential energy surface of interlayer interaction in two-dimensional materials by first spatial Fourier harmonics
• Atomistic mechanism of friction force independence on the normal load and other friction laws for dynamic structural superlubricity
• Edge stacking dislocations in two-dimensional bilayers with a small lattice mismatch
• Interlayer interaction, shear vibrational mode, and tribological properties of two-dimensional bilayers with a commensurate moiré pattern