Raman spectra of twisted bilayer graphene close to the magic angle

Abstract

In this work, we study the Raman spectra of twisted bilayer graphene samples as a function of their twist-angles ($\theta$), ranging from 0.03${}^{\circ }$ to 3.40${}^{\circ }$, where local $\theta$ are determined by analysis of their associated moire superlattices, as imaged by scanning microwave impedance microscopy. Three standard excitation laser lines are used (457, 532, and 633 nm wavelengths), and the main Raman active graphene bands (G and 2D) are considered. Our results reveal that electron-phonon interaction influences the G band's linewidth close to the magic angle regardless of laser excitation wavelength. Also, the 2D band lineshape in the $\theta$ < 1${}^{\circ }$ regime is dictated by crystal lattice and depends on both the Bernal (AB and BA) stacking bilayer graphene and strain soliton regions (SP). We propose a geometrical model to explain the 2D lineshape variations, and from it, we estimate the SP width when moving towards the magic angle.

References in corpus (37)

• Electric Field Effect in Atomically Thin Carbon Films
• The Raman Fingerprint of Graphene
• Van der Waals heterostructures
• Magic-angle graphene superlattices: a new platform for unconventional superconductivity
• Raman spectroscopy as a versatile tool for studying the properties of graphene
• Boron nitride substrates for high-quality graphene electronics
• Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
• 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
• Born-Oppenheimer Breakdown in Graphene
• Observation of Van Hove singularities in twisted graphene layers
• Optical Separation of Mechanical Strain from Charge Doping in Graphene
• Flat Bands in Slightly Twisted Bilayer Graphene
• Kohn Anomalies and Electron-Phonon Interaction in Graphite
• Atomic and electronic reconstruction at van der Waals interface in twisted bilayer graphene
• Theory of double-resonant Raman spectra in graphene: intensity and line shape of defect-induced and two-phonon bands
• Raman spectroscopy study of rotated double-layer graphene: Misorientation-angle dependence of electronic structure
• Strain Solitons and Topological Defects in Bilayer Graphene
• Twistronics: Manipulating the Electronic Properties of Two-dimensional Layered Structures through their Twist Angle
• Theory of phonon-mediated superconductivity in twisted bilayer graphene
• Decoupling superconductivity and correlated insulators in twisted bilayer graphene
• Mapping the twist angle and unconventional Landau levels in magic angle graphene
• Twisted Bilayer Graphene: A Phonon Driven Superconductor
• Phonon renormalisation in doped bilayer graphene
• Phonon-induced giant linear-in-$T$ resistivity in magic angle twisted bilayer graphene: Ordinary strangeness and exotic superconductivity
• Structural and electronic transformation in low-angle twisted bilayer graphene
• Observation of Low Energy Raman Modes in Twisted Bilayer Graphene
• G band Raman double resonance in twisted bilayer graphene: an evidence of band splitting and folding
• Splitting of the Raman $2D$ band of graphene subjected to strain
• Raman-scattering study of the phonon dispersion in twisted bi-layer graphene
• Valley Jahn-Teller effect in twisted bilayer graphene
• Observation of the Kohn anomaly near the K point of bilayer graphene
• Electronic localization in small-angle twisted bilayer graphene
• Fermi energy dependence of first- and second-order Raman spectra in graphene: Kohn anomaly and quantum interference effect
• The limits of Near Field Immersion Microwave Microscopy evaluated by imaging bilayer graphene Moiré patterns

Cited by in corpus (8)

• Symmetry Origin of Lattice Vibration Modes in Twisted Multilayer Graphene: Phasons vs Moiré Phonons
• An atomistic insight into moiré reconstruction in Twisted Bilayer Graphene beyond the magic angle
• Probing interlayer interactions and commensurate-incommensurate transition in twisted bilayer graphene through Raman spectroscopy
• Electron-phonon coupling in a magic-angle twisted-bilayer graphene device
• Anomalies in G and 2D Raman Modes of Twisted Bilayer Graphene Near the Magic Angle
• Interference effects in polarization controlled Rayleigh scattering in twisted bilayer graphene
• Direct observation of flat bands in near-magic-angle twisted bilayer CVD graphene
• Electronic properties of twisted multilayer graphene