Pressure induced gap modulation and topological transitions in twisted bilayer and double bilayer graphene

Abstract

We study the electronic and topological properties of fully relaxed twisted bilayer (TBG) and double bilayer (TDBG) graphene under perpendicular pressure. An approach has been proposed to obtain the equilibrium in-plane structural deformation and out-of-plane corrugation in moiré superlattices under pressure. We find that the in-plane relaxation becomes much stronger under higher pressure, while the corrugation height in each layer is maintained. The comparison between band structures of relaxed and rigid structures demonstrates that not only the gaps on the electron and hole sides (${\Delta }_e$ and ${\Delta }_h$) are significantly underestimated without relaxation but also the detailed dispersions of the middle bands of rigid structures are rather different from those of relaxed systems. ${\Delta }_e$ and ${\Delta }_h$ in TBG reach maximum values around critical pressures with narrowest middle bands. Topological transitions occur in TDBG under pressure with the middle valence and conduction bands in one valley touching and their Chern numbers transferred to each other. The pressure can also tune the gap at the neutrality point of TDBG, which becomes closed for a pressure range and reopened under higher pressure. The behavior of electronic structure of supertlattices under pressure is sensitive to the twist angle $\theta$ with the critical pressures generally increase with $\theta$.

arXiv comment11 pages, 7 figures

References in corpus (38)

• The electronic properties of graphene
• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Berry Phase Effects on Electronic Properties
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• Van der Waals density functionals applied to solids
• Moire bands in twisted double-layer graphene
• Tuning superconductivity in twisted bilayer graphene
• Emergent ferromagnetism near three-quarters filling in twisted bilayer graphene
• Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
• Graphene bilayer with a twist: electronic structure
• Flat Bands in Slightly Twisted Bilayer Graphene
• Origin of Magic Angles in Twisted Bilayer Graphene
• Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene
• Electric Field Tunable Correlated States and Magnetic Phase Transitions in Twisted Bilayer-Bilayer Graphene
• Continuum Model of the Twisted Bilayer
• Strain Solitons and Topological Defects in Bilayer Graphene
• Lattice relaxation and energy band modulation in twisted bilayer graphenes
• SCAN+rVV10: A promising van der Waals density functional
• Energy Spectrum and Quantum Hall Effect in Twisted Bilayer Graphene
• Numerical studies of confined states in rotated bilayers of graphene
• Dynamic band structure tuning of graphene moiré superlattices with pressure
• Relaxation and Domain Formation in Incommensurate 2D Heterostructures
• Quantum valley Hall effect, orbital magnetism, and anomalous Hall effect in twisted multilayer graphene systems
• Pressure dependence of the magic twist angle in graphene superlattices
• Relaxation of moiré patterns for slightly misaligned identical lattices: graphene on graphite
• Theory of correlated insulating behaviour and spin-triplet superconductivity in twisted double bilayer graphene
• Flatbands in twisted double bilayer graphene
• Electronic Structure Theory of Weakly Interacting Bilayers
• Band structure and topological property of twisted double bilayer graphenes
• The crucial role of atomic corrugation on the flat bands and energy gaps of twisted bilayer graphene at the "magic angle" $\theta \sim 1.08^{\circ }$
• Continuum models for twisted bilayer graphene: the effects of lattice deformation and hopping parameter
• Structural and electronic transformation in low-angle twisted bilayer graphene
• Bending modes, anharmonic effects and thermal expansion coefficient in single layer and multilayer graphene
• Structure of twisted and buckled bilayer graphene
• Intrinsic Band Gap and Electrically Tunable Flat Bands in Twisted Double Bilayer Graphene
• Pressure Induced Compression of Flatbands in Twisted Bilayer Graphene
• Minimum model for the electronic structure of twisted bilayer graphene and related structures
• Is Twisted Bilayer Graphene Stable under Shear?

Cited by in corpus (16)

• Effect of bilayer stacking on the atomic and electronic structure of twisted double bilayer graphene
• Tailoring the band structure of twisted double bilayer graphene with pressure
• Transport measurements on van der Waals heterostructures under pressure
• Symmetry breaking in the double moiré superlattices of relaxed twisted bilayer graphene on hexagonal boron nitride
• Full Slonczewski-Weiss-McClure parametrization of few-layer twistronic graphene
• Energetic stability and spatial inhomogeneity in the local electronic structure of relaxed twisted trilayer graphene
• Trigonal Warping, Satellite Dirac Points and Multiple Field Tuned Topological Transitions in Twisted Double Bilayer Graphene
• Pressure-Driven Moiré Potential Enhancement and Tertiary Gap Opening in Graphene/h-BN Heterostructure
• Hydrostatic pressure control of the spin-orbit proximity effect, spin relaxation, and thermoelectricity in a phosphorene-WSe${}_2$ heterostructure
• Emergence of intrinsically isolated flat bands and their topology in fully relaxed twisted multi-layer graphene
• Semimetallic and semiconducting graphene-hBN multilayers with parallel or reverse stacking
• Magic angle and plasmon mode engineering in twisted trilayer graphene with pressure
• Magic distances in twisted bilayer graphene
• Effective K valley Hamiltonian for TMD bilayers under pressure and application to twisted bilayers with pressure-induced topological phase transitions
• Electronic properties of twisted multilayer graphene
• Chiral topological superconductivity in twisted bilayer and double bilayer graphene