Non-identical moiré twins in bilayer graphene

Abstract

The superlattice obtained by aligning a monolayer graphene and boron nitride (BN) inherits from the hexagonal lattice a sixty degrees periodicity with the layer alignment. It implies that, in principle, the properties of the heterostructure must be identical for 0${}^{\circ }$ and 60${}^{\circ }$ of layer alignment. Here, we demonstrate, using dynamically rotatable van der Waals heterostructures, that the moiré superlattice formed in a bilayer graphene/BN has different electronic properties at 0${}^{\circ }$ and 60${}^{\circ }$ of alignment. Although the existence of these non-identical moiré twins is explained by different relaxation of the atomic structures for each alignment, the origin of the observed valley Hall effect remains to be explained. A simple Berry curvature argument do not hold to explain the hundred and twenty degrees periodicity of this observation. Our results highlight the complexity of the interplay between mechanical and electronic properties on moiré structure and the importance of taking into account atomic structure relaxation to understand its electronic properties.

References in corpus (31)

• Double-slit photoelectron interference in strong-field ionization of the neon dimer
• Energy gaps, topological insulator state and zero-field quantum Hall effect in graphene by strain engineering
• Massive Dirac fermions and Hofstadter butterfly in a van der Waals heterostructure
• Cloning of Dirac fermions in graphene superlattices
• Optimized Tersoff and Brenner empirical potential parameters for lattice dynamics and phonon thermal transport in carbon nanotubes and graphene
• Commensurate-incommensurate transition for graphene on hexagonal boron nitride
• Detecting Topological Currents in Graphene Superlattices
• Effects of Strain on Electronic Properties of Graphene
• Twistable electronics with dynamically rotatable heterostructures
• Proximity-induced ferromagnetism in graphene revealed by anomalous Hall effect
• Generation and detection of pure valley current by electrically induced Berry curvature in bilayer graphene
• Gate-tunable Topological Valley Transport in Bilayer Graphene
• Origin of band gaps in graphene on hexagonal boron nitride
• Electronic properties of graphene hexagonal boron nitride moiré superlattice
• Fractional fractal quantum Hall effect in graphene superlattices
• Tunable crystal symmetry in graphene-boron nitride heterostructures with coexisting moiré superlattices
• Nonlocal Charge Transport Mediated by Spin Diffusion in the Spin-Hall Effect Regime
• New generation of moiré superlattices in doubly aligned hBN/graphene/hBN heterostructures
• Topological Bloch Bands in Graphene Superlattices
• Observation of the quantum valley Hall state in ballistic graphene superlattices
• Tunable and giant valley-selective Hall effect in gapped bilayer graphene
• Long-range nontopological edge currents in charge-neutral graphene
• Gap Opening in Twisted Double Bilayer Graphene by Crystal fields
• Transport spectroscopy of ultraclean tunable band gaps in bilayer graphene
• Topological Valley Currents in Bilayer Graphene/Hexagonal Boron Nitride Superlattices
• Nonlocal topological valley transport at large valley Hall angles
• Coherent Jetting behind a gate-defined Channel in Bilayer Graphene
• High quality electrostatically defined hall bars in monolayer graphene
• Valley Hall Effect and Non-Local Resistance in Locally Gapped Graphene
• Global strain-induced scalar potential in graphene devices
• Topological valley currents via ballistic edge modes in graphene superlattices near the primary Dirac point

Cited by in corpus (7)

• de Haas-van Alphen spectroscopy and fractional quantization of magnetic-breakdown orbits in moiré graphene
• Non-conservation of the valley density and its implications for the observation of the valley Hall effect
• Klein tunneling degradation and enhanced Fabry-Pérot interference in graphene/h-BN moiré-superlattice devices
• Tunable atomically enhanced moiré Berry curvatures in twisted triple bilayer graphene
• Impact of the angular alignment on the crystal field and intrinsic doping of bilayer graphene/BN heterostructures
• Hexagonal boron nitride/bilayer graphene moiré superlattices in the Dirac-material family: energy-band engineering and carrier doping by dual gating
• Magic-angle twisted bilayer graphene under orthogonal and in-plane magnetic fields