Probing interlayer interactions and commensurate-incommensurate transition in twisted bilayer graphene through Raman spectroscopy

Fuente: arXiv
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Autores principales: Pandey, Vineet, Mishra, Subhendu, Maity, Nikhilesh, Paul, Sourav, B, Abhijith M, Roy, Ajit, Glavin, Nicholas R, Watanabe, Kenji, Taniguchi, Takashi, Singh, Abhishek Kumar, Kochat, Vidya
Formato: Preprint
Publicado: 2023
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author Pandey, Vineet
Mishra, Subhendu
Maity, Nikhilesh
Paul, Sourav
B, Abhijith M
Roy, Ajit
Glavin, Nicholas R
Watanabe, Kenji
Taniguchi, Takashi
Singh, Abhishek Kumar
Kochat, Vidya
author_facet Pandey, Vineet
Mishra, Subhendu
Maity, Nikhilesh
Paul, Sourav
B, Abhijith M
Roy, Ajit
Glavin, Nicholas R
Watanabe, Kenji
Taniguchi, Takashi
Singh, Abhishek Kumar
Kochat, Vidya
contents Twisted 2D layered materials have garnered a lot of attention recently as a class of 2D materials whose interlayer interactions and electronic properties are dictated by the relative rotation / twist angle between the adjacent layers. In this work, we explore a prototype of such a twisted 2D system, artificially stacked twisted bilayer graphene (TBLG), where we probe the changes in the interlayer interactions and electron-phonon scattering pathways as the twist angle is varied from 0° to 30°, using Raman spectroscopy. The long range Moiré potential of the superlattice gives rise to additional intravalley and intervalley scattering of the electrons in TBLG which have been investigated through their Raman signatures. The density functional theory (DFT) calculations of the electronic band structure of the TBLG superlattices was found to be in agreement with the resonant Raman excitations across the van Hove singularities in the valence and conduction bands predicted for TBLG due to hybridization of bands from the two layers. We also observe that the relative rotation between the graphene layers has a marked influence on the second order overtone and combination Raman modes signalling a commensurate-incommensurate transition in TBLG as the twist angle increases. This serves as a convenient and rapid characterization tool to determine the degree of commensurability in TBLG systems.
format Preprint
id arxiv_https___arxiv_org_abs_2311_01029
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Probing interlayer interactions and commensurate-incommensurate transition in twisted bilayer graphene through Raman spectroscopy
Pandey, Vineet
Mishra, Subhendu
Maity, Nikhilesh
Paul, Sourav
B, Abhijith M
Roy, Ajit
Glavin, Nicholas R
Watanabe, Kenji
Taniguchi, Takashi
Singh, Abhishek Kumar
Kochat, Vidya
Materials Science
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
Twisted 2D layered materials have garnered a lot of attention recently as a class of 2D materials whose interlayer interactions and electronic properties are dictated by the relative rotation / twist angle between the adjacent layers. In this work, we explore a prototype of such a twisted 2D system, artificially stacked twisted bilayer graphene (TBLG), where we probe the changes in the interlayer interactions and electron-phonon scattering pathways as the twist angle is varied from 0° to 30°, using Raman spectroscopy. The long range Moiré potential of the superlattice gives rise to additional intravalley and intervalley scattering of the electrons in TBLG which have been investigated through their Raman signatures. The density functional theory (DFT) calculations of the electronic band structure of the TBLG superlattices was found to be in agreement with the resonant Raman excitations across the van Hove singularities in the valence and conduction bands predicted for TBLG due to hybridization of bands from the two layers. We also observe that the relative rotation between the graphene layers has a marked influence on the second order overtone and combination Raman modes signalling a commensurate-incommensurate transition in TBLG as the twist angle increases. This serves as a convenient and rapid characterization tool to determine the degree of commensurability in TBLG systems.
title Probing interlayer interactions and commensurate-incommensurate transition in twisted bilayer graphene through Raman spectroscopy
topic Materials Science
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2311.01029