Valley-Current Splitter in Minimally Twisted Bilayer Graphene

Abstract

We study the electronic transport properties at the intersection of three topological zero-lines as the elementary current partition node that arises in minimally twisted bilayer graphene. Unlike the partition laws of two intersecting zero-lines, we find that (i) the incoming current can be partitioned into both left-right adjacent topological channels and that (ii) the forward-propagating current is nonzero. By tuning the Fermi energy from the charge-neutrality point to a band edge, the currents partitioned into the three outgoing channels become nearly equal. Moreover, we find that current partition node can be designed as a perfect valley filter and energy splitter controlled by electric gating. By changing the relative electric field magnitude, the intersection of three topological zero-lines can transform smoothly into a single zero line, and the current partition can be controlled precisely. We explore the available methods for modulating this device systematically by changing the Fermi energy, the energy gap size, and the size of central gapless region. The current partition is also influenced by magnetic fields and the system size. Our results provide a microscopic depiction of the electronic transport properties around a unit cell of minimally twisted bilayer graphene and have far-reaching implications in the design of electron-beam splitters and interferometer devices.

arXiv commentarXiv admin note: substantial text overlap with arXiv:1904.12826

References in corpus (31)

• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene
• Strain Solitons and Topological Defects in Bilayer Graphene
• Topological confinement in bilayer graphene
• Photonic crystals for nano-light in moiré graphene superlattices
• Dynamic band structure tuning of graphene moiré superlattices with pressure
• Topologically Protected Helical States in Minimally Twisted Bilayer Graphene
• Gate-controlled topological conducting channels in bilayer graphene
• Quantum valley Hall effect, orbital magnetism, and anomalous Hall effect in twisted multilayer graphene systems
• Theory of correlated insulating behaviour and spin-triplet superconductivity in twisted double bilayer graphene
• Band structure and topological property of twisted double bilayer graphenes
• Electronic Highways in Bilayer Graphene
• Valley-Hall Kink and Edge States in Multilayer Graphene
• A valley valve and electron beam splitter
• Helical networks in twisted bilayer graphene under interlayer bias
• Transport through a network of topological states in twisted bilayer graphene
• Helical Network Model for Twisted Bilayer Graphene
• Giant oscillations in a triangular network of one-dimensional states in marginally twisted graphene
• Electrically tunable gauge fields in tiny-angle twisted bilayer graphene
• Heterostrain engineering on twisted graphene bilayer around the first magic angle
• Accurate Gap Determination in Monolayer and Bilayer Graphene/h-BN Moire Superlattices
• Current partition at topological zero-line intersections
• Experimental evidence for non-Abelian gauge potentials in twisted graphene bilayers
• Twists and The Electronic Structure of Graphitic Materials
• Designing multi-directional energy-splitters and topological valley supernetworks
• Superconductor versus insulator in twisted bilayer graphene
• Zero-line modes at stacking faulted domain walls in multilayer graphene
• Gate tunable current partition in graphene based topological zero lines
• Metallic Network of Topological Domain Walls
• The role of geometry and topological defects in the 1D zero-line modes of graphene
• Topological Zero-Line Modes in Folded Bilayer Graphene

Cited by in corpus (6)

• Valley protected one-dimensional states in small-angle twisted bilayer graphene
• Localized states coupled to a network of chiral modes in minimally twisted bilayer graphene
• Arrays of one-dimensional conducting channels in minimally twisted bilayer graphene
• Physical Origin of Current Partition at a Topological Trifurcation
• Effects of spin-orbit coupling in a valley chiral kagomé network
• Pseudospin-one particles in the time-periodic dice lattice: A new approach to transport control