The Interlayer Shear Modes in Twisted Multi-layer Graphenes: Interlayer coupling, Davydov Splitting and Intensity Resonance

  title={The Interlayer Shear Modes in Twisted Multi-layer Graphenes: Interlayer coupling, Davydov Splitting and Intensity Resonance},
  author={Jiangbin Wu and Xin Zhang and M. Ijas and W. P. Han and Xiao-fen Qiao and Xiaoli Li and De-sheng Jiang and Andrea C. Ferrari and Pingheng Tan},
Graphene and other two-dimensional crystals can be combined to form various hybrids and heterostructures, creating materials on demand, in which the interlayer coupling at the interface leads to modified physical properties as compared to their constituents. Here, by measuring Raman spectra of shear modes, we probe the coupling at the interface between two artificially-stacked few-layer graphenes rotated with respect to each other. The strength of interlayer coupling between the two interface… 

Ultralow-Frequency Raman Spectroscopy of Two-dimensional Materials

In two-dimensional materials (2DMs), atoms within one layer (in-plane) are joined by covalent bonds, whereas van der Waals (vdW) interactions keep the layers together. Raman spectroscopy is a

Phonon physics in twisted two-dimensional materials

As one of the most effective manipulation means to control the physical properties of two-dimensional van der Waals stacking materials, the twisted angle periodically regulates the interlayer

Intralayer Phonons in Multilayer Graphene Moiré Superlattices

Moiré pattern in twisted multilayers (tMLs) induces many emergent phenomena by subtle variation of atomic registry to modulate quasiparticles and their interactions, such as superconductivity, moiré

Interlayer coupling in two-dimensional semiconductor materials

Two-dimensional (2D) graphene-like layered semiconductors provide a new platform for materials research because of their unique mechanical, electronic and optical attributes. Their in-plane covalent

Lattice vibration and Raman scattering of two-dimensional van der Waals heterostructure

Research on two-dimensional (2D) materials and related van der Waals heterostructures (vdWHs) is intense and remains one of the leading topics in condensed matter physics. Lattice vibrations or

Low-energy moiré phonons in twisted bilayer van der Waals heterostructures

We develop a low-energy continuum model for phonons in twisted moir´e bilayers, based on a configuration-space approach. In this approach, interatomic force constants are obtained from density

Raman Spectroscopy of Monolayer and Multilayer Graphenes

The discovery of monolayer graphene in 2004 has triggered a great effort to investigate the fundamental properties and applications of all two-dimensional materials (2DMs). Monolayer graphene (1LG)

Stacking-dependent interlayer phonons in 3R and 2H MoS2

We have investigated the interlayer shear and breathing phonon modes in MoS2 with pure 3R and 2H stacking order by using polarization-dependent ultralow-frequency Raman spectroscopy. We observe up to

Spatial mapping of a low-frequency combination Raman mode in twisted bilayer graphene

The exotic properties of twisted bilayer graphene (tBLG) are profoundly affected by interlayer interactions, which can be sensitively probed by the low-frequency Raman modes. However, conventional

Electronic Raman Scattering in Twistronic Few-Layer Graphene.

We study electronic contribution to the Raman scattering signals of two-, three- and four-layer graphene with layers at one of the interfaces twisted by a small angle with respect to each other. We



Angle-resolved Raman imaging of interlayer rotations and interactions in twisted bilayer graphene.

This work combines two direct imaging techniques, dark-field transmission electron microscopy (DF-TEM) and widefield Raman imaging, to establish a robust, one-to-one correlation between twist angle and Raman intensity in twisted bilayer graphene (tBLG).

The shear mode of multilayer graphene.

The interlayer shear mode of FLGs, ranging from bilayer graphene (BLG) to bulk graphite, is uncovered, and it is suggested that the corresponding Raman peak measures the interlayer coupling.

Interlayer breathing and shear modes in few-trilayer MoS2 and WSe2.

The ultralow frequency interlayer breathing and shear modes in few-layer MoS2 and WSe2, prototypical layered TMDs, are uncovered using both Raman spectroscopy and first principles calculations and can be perfectly described using a simple linear chain model with only nearest-neighbor interactions.

Theory of the Raman spectrum of rotated double-layer graphene

We study theoretically the Raman spectrum of the rotated double-layer graphene, consisting of two graphene layers rotated with respect to each other by an arbitrary angle \theta. We find a relatively

Stacking-dependent optical conductivity of bilayer graphene.

The results reveal that the optical conductivity measurements of graphene layers indeed provide an efficient way to select graphene films with desirable electronic and optical properties, which would greatly help the future application of those large-scale misoriented graphene films in photonic devices.

Optical Absorption in Twisted Bilayer Graphene

We theoretically study the optical absorption property of twisted bilayer graphenes with various stacking geometries, and demonstrate that the spectroscopic characteristics serve as a fingerprint to

Ultralow-frequency shear modes of 2-4 layer graphene observed in scroll structures at edges

The in-plane shear modes between neighbor-layers of 2-4 layer graphenes (LGs) and the corresponding graphene scrolls rolled up by 2-4LGs were investigated by Raman scattering. In contrast to that

Raman spectroscopy study of rotated double-layer graphene: misorientation-angle dependence of electronic structure.

A systematic Raman study of unconventionally stacked double-layer graphene finds that the spectrum strongly depends on the relative rotation angle between layers, and reveals changes in electronic band structure due to the interlayer interaction are responsible for the observed spectral features.

Phonons in few-layer graphene and interplanar interaction : A first-principles study

We use first-principles density-functional theory calculations to determine the vibrational properties of ultrathin n(1,2,…,7) -layer graphene films and present a detailed analysis of their

Raman spectroscopy as a versatile tool for studying the properties of graphene.

The state of the art, future directions and open questions in Raman spectroscopy of graphene are reviewed, and essential physical processes whose importance has only recently been recognized are described.