Phonons in Twisted Transition Metal Dichalcogenide Bilayers ("Twistnonics"): Ultra-soft Phasons, and a transition from Superlubric to Pinned Phase

Abstract

The tunability of the interlayer coupling by twisting one layer with respect to another layer of two-dimensional materials provides a unique way to manipulate the phonons and related properties. We refer to this engineering of phononic properties as "Twistnonics". We study the effects of twisting on low-frequency shear (SM) and layer breathing (LBM) modes in transition metal dichalcogenide (TMD) bilayer using atomistic classical simulations. We show that these low-frequency modes are extremely sensitive to twist and can be used to infer the twist angle. We find unique "ultra-soft" phason modes (frequency $\lesssim 1\mathrm{c}{\mathrm{m}}^{-1}$, comparable to acoustic modes) for any non-zero twist, corresponding to an \textit{effective} translation of the moir{é} lattice by relative displacement of the constituent layers in a non-trivial way. Unlike the acoustic modes, the velocity of the phason modes is quite sensitive to twist angle. As twist angle decreases, ($\theta \lesssim 3^{\circ },\gtrsim 57^{\circ }$) the ultra-soft modes represent the acoustic modes of the "emergent" soft moir{é} scale lattice. Also, new high-frequency SMs appear, identical to those in stable bilayer TMD ($\theta =0°/60°$), due to the overwhelming growth of stable stacking regions in relaxed twisted structures. Furthermore, we find remarkably different structural relaxation as $\theta \to 0^{\circ }$, $\to 60^{\circ }$ due to sub-lattice symmetry breaking. Our study reveals the possibility of an intriguing $\theta$ dependent superlubric to pinning behavior and of the existence of ultra-soft modes in \textit{all} two-dimensional (2D) materials.

arXiv commentVersion 3 (12 pages)

References in corpus (39)

• 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
• Superconductors, Orbital Magnets, and Correlated States in Magic Angle Bilayer Graphene
• Magic Angle Spectroscopy
• Origin of Magic Angles in Twisted Bilayer Graphene
• Topological insulators in twisted transition metal dichalcogenide homobilayers
• Localization of Dirac electrons by Moire patterns in graphene bilayers
• Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene
• Interlayer breathing and shear modes in few-trilayer MoS2 and WSe2
• Twistable electronics with dynamically rotatable heterostructures
• Strain Solitons and Topological Defects in Bilayer Graphene
• Lattice relaxation and energy band modulation in twisted bilayer graphenes
• Twistronics: Manipulating the Electronic Properties of Two-dimensional Layered Structures through their Twist Angle
• Strange metal in magic-angle graphene with near Planckian dissipation
• Electronic structure of turbostratic graphene
• Ultraflat bands and shear solitons in Moiré patterns of twisted bilayer transition metal dichalcogenides
• Photonic crystals for nano-light in moiré graphene superlattices
• Phonon scattering dominated electron transport in twisted bilayer graphene
• Parametrization of Stillinger-Weber Potential Based on Valence Force Field Model: Application to Single-Layer MoS2 and Black Phosphorus
• Relaxation and Domain Formation in Incommensurate 2D Heterostructures
• Topologically Protected Helical States in Minimally Twisted Bilayer Graphene
• Robust Superlubricity in Graphene/h-BN Heterojunctions
• Phonon-induced giant linear-in-$T$ resistivity in magic angle twisted bilayer graphene: Ordinary strangeness and exotic superconductivity
• The crucial role of atomic corrugation on the flat bands and energy gaps of twisted bilayer graphene at the "magic angle" $\theta \sim 1.08^{\circ }$
• Structural and electronic transformation in low-angle twisted bilayer graphene
• Strong electron-phonon coupling, electron-hole asymmetry, and nonadiabaticity in magic-angle twisted bilayer graphene
• Moiré phonons in the twisted bilayer graphene
• Phonon Quasi-Particles and Anharmonic Free Energy in Complex Systems
• Superlubricity - a new perspective on an established paradigm
• Direct Observation of Acoustic Phonon Confinement in Free-Standing Semiconductor Nanowires
• Specific Heat of Twisted Bilayer Graphene
• Moiré-pattern fluctuations and electron-phason coupling in twisted bilayer graphene
• Valley Jahn-Teller effect in twisted bilayer graphene
• Experimental observation of the Aubry transition in two-dimensional colloidal monolayers
• Frictional Transition from Superlubric Islands to Pinned Monolayers
• Commensurate-incommensurate phase transition and a network of domain walls in bilayer graphene with a biaxially stretched layer
• Interaction effects and superconductivity signatures in twisted double-bilayer WSe${}_2$
• Temperature Dependent Layer Breathing Modes in Two Dimensional Materials

Cited by in corpus (37)

• Origin and Evolution of Ultraflatbands in Twisted Bilayer Transition Metal Dichalcogenides: Realization of Triangular Quantum Dot Array
• Structural relaxation and low energy properties of Twisted Bilayer Graphene
• Large-scale mapping of moiré superlattices by Raman imaging of interlayer breathing mode and moiré phonons
• Moiré and beyond in transition metal dichalcogenide twisted bilayers
• Tuning the lattice thermal conductivity in van-der-Waals structures through rotational (dis)ordering
• TMDs as a platform for spin liquid physics: A strong coupling study of twisted bilayer WSe${}_2$
• Reconstruction of moiré lattices in twisted transition metal dichalcogenide bilayers
• Chiral Phonons in Moiré Superlattices
• Low-frequency Raman scattering in WSe${}_2$-MoSe${}_2$ heterobilayers: Evidence for atomic reconstruction
• Relaxation effects in twisted bilayer molybdenum disulfide: structure, stability, and electronic properties
• Moiré induced topology and flat bands in twisted bilayer WSe${}_2$: A first-principles study
• Degradation of phonons in disordered moiré superlattices
• Symmetry Origin of Lattice Vibration Modes in Twisted Multilayer Graphene: Phasons vs Moiré Phonons
• Chiral valley phonons and flat phonon bands in moiré materials
• Low-energy moiré phonons in twisted bilayer van der Waals heterostructures
• Moiré phonons and impact of electronic symmetry breaking in twisted trilayer graphene
• Moiré phonons in graphene/hexagonal boron nitride moiré superlattice
• Exchange-bias controlled correlations in magnetically encapsulated twisted van der Waals dichalcogenides
• Extended linear-in-$T$ resistivity due to electron-phason scattering in moiré superlattices
• Spin-orbit correlations and exchange-bias control in twisted Janus dichalcogenide multilayers
• Flat and tunable moire phonons in twisted transition-metal dichalcogenides
• Glassy heat capacity from overdamped phasons and a hypothetical phason-induced superconductivity in incommensurate structures
• Electrons surf phason waves in moiré bilayers
• Influence of different exchange-correlation potentials on twisted structures of bilayer XS2 (X= Mo, Cr)
• Mesoscopic Stacking Reconfigurations in Stacked van der Waals Film
• Low-temperature thermal transport in moiré superlattices
• Atomic relaxation and flat bands in strain-engineered transition metal dichalcogenide bilayer moiré systems
• PARPHOM: PARallel PHOnon calculator for Moiré systems
• Addressing the spin-valley flavors in moir'e mini-bands of MoS2
• Phonon Linewidths in Twisted Bilayer Graphene near Magic Angle
• Long wavelength interdomain phonons and instability of dislocations in small-angle twisted bilayers
• Electric backaction on moiré mechanics
• Charged moiré phonons in twisted bilayer graphene
• Phonon Renormalization in Reconstructed MoS${}_2$ Moiré Superlattices
• Quasi-bound layer-breathing phonons inside perfect dislocations of lattice-relaxed twisted bilayers
• Moire-Engineered Excitonic Landscape and Phonon-Mediated Recombination in Twisted WSe2 Bilayers
• Twister: Construction and structural relaxation of commensurate moiré superlattices