Ultrafast formation of transient 2D diamond-like structure in twisted bilayer graphene
arXiv:2003.08341 · doi:10.1103/PhysRevB.102.155431
Abstract
Due to the absence of matching carbon atoms at honeycomb centers with carbon atoms in adjacent graphene sheets, theorists predicted that a sliding process is needed to form AA, AB, or ABC stacking when directly converting graphite into sp3 bonded diamond. Here, using twisted bilayer graphene, which naturally provides AA and AB stacking configurations, we report the ultrafast formation of a transient 2D diamond-like structure (which is not observed in aligned graphene) under femtosecond laser irradiation. This photo-induced phase transition is evidenced by the appearance of new bond lengths of 1.94A and 3.14A in the time-dependent differential pair distribution function using MeV ultrafast electron diffraction. Molecular dynamics and first principles calculation indicate that sp3 bonds nucleate at AA and AB stacked areas in moire pattern. This work sheds light on the direct graphite-to-diamond transformation mechanism, which has not been fully understood for more than 60 years.
References in corpus (23)
- Electric Field Effect in Atomically Thin Carbon Films
- Magic-angle graphene superlattices: a new platform for unconventional superconductivity
- Correlated Insulator Behaviour at Half-Filling in Magic Angle Graphene Superlattices
- Tuning superconductivity in twisted bilayer graphene
- Thermal properties of graphene: Fundamentals and applications
- Moiré Excitons in Van der Waals Heterostructures
- Signatures of moiré-trapped valley excitons in MoSe/WSe heterobilayers
- Strong light-matter coupling in two-dimensional atomic crystals
- High-accuracy first-principles determination of the structural, vibrational and thermodynamical properties of diamond, graphite, and derivatives
- Observation of Moiré Excitons in WSe2/WS2 Heterostructure Superlattices
- Controlling electron-phonon interactions in graphene at ultra high carrier densities
- Magic Angle Spectroscopy
- Resonantly hybridised excitons in moiré superlattices in van der Waals heterostructures
- Charge-Order and Broken Rotational Symmetry in Magic Angle Twisted Bilayer Graphene
- Spectroscopic signatures of many-body correlations in magic angle twisted bilayer graphene
- On the roughness of single- and bi-layer graphene membranes
- Twistronics: Manipulating the Electronic Properties of Two-dimensional Layered Structures through their Twist Angle
- Two-dimensional semiconductors in the regime of strong light-matter coupling
- Coherent and incoherent electron-phonon coupling in graphite observed with radio-frequency compressed ultrafast electron diffraction
- Direct observation of optically induced transient structures in graphite using ultrafast electron crystallography
- Mapping momentum-dependent electron-phonon coupling and non-equilibrium phonon dynamics with ultrafast electron diffuse scattering
- Sub-picosecond photo-induced displacive phase transition in two-dimensional MoTe
- Comment on "Structural Preablation Dynamics of Graphite Observed by Ultrafast Electron Crystallography"