Phonon Linewidths in Twisted Bilayer Graphene near Magic Angle
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| Main Authors: | , , , |
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| Format: | Preprint |
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2024
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| _version_ | 1866912063512641536 |
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| author | Mandal, Shinjan Maity, Indrajit Krishnamurthy, H. R. Jain, Manish |
| author_facet | Mandal, Shinjan Maity, Indrajit Krishnamurthy, H. R. Jain, Manish |
| contents | We present a computational study of the phonon linewidths in twisted bilayer graphene arising from electron-phonon interactions and anharmonic effects. The electronic structure is calculated using distance-dependent transfer integrals based on the atomistic Slater-Koster tight-binding formalism, including electron-electron interactions treated at the Hartree level, and the phonons are calculated using classical force fields. These ingredients are used to calculate the phonon linewidths arising from electron-phonon interactions. Furthermore, anharmonic effects on the linewidths are computed using the mode-projected velocity autocorrelation function obtained from classical molecular dynamics. We predict a moiré potential induced splitting of this mode, which arises due to contributions from high symmetry stacking regions. Our findings show that both electron-phonon and anharmonic effects have a significant impact on the linewidth of the Raman active G mode near the magic angle. |
| format | Preprint |
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arxiv_https___arxiv_org_abs_2403_09692 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Phonon Linewidths in Twisted Bilayer Graphene near Magic Angle Mandal, Shinjan Maity, Indrajit Krishnamurthy, H. R. Jain, Manish Mesoscale and Nanoscale Physics Materials Science We present a computational study of the phonon linewidths in twisted bilayer graphene arising from electron-phonon interactions and anharmonic effects. The electronic structure is calculated using distance-dependent transfer integrals based on the atomistic Slater-Koster tight-binding formalism, including electron-electron interactions treated at the Hartree level, and the phonons are calculated using classical force fields. These ingredients are used to calculate the phonon linewidths arising from electron-phonon interactions. Furthermore, anharmonic effects on the linewidths are computed using the mode-projected velocity autocorrelation function obtained from classical molecular dynamics. We predict a moiré potential induced splitting of this mode, which arises due to contributions from high symmetry stacking regions. Our findings show that both electron-phonon and anharmonic effects have a significant impact on the linewidth of the Raman active G mode near the magic angle. |
| title | Phonon Linewidths in Twisted Bilayer Graphene near Magic Angle |
| topic | Mesoscale and Nanoscale Physics Materials Science |
| url | https://arxiv.org/abs/2403.09692 |