# Magnetophonon spectroscopy of Dirac Fermion scattering by transverse and longitudinal acoustic phonons in graphene

## TL;DR

This paper investigates magnetophonon resonances in graphene, showing that low energy transverse acoustic phonons dominate electron scattering, and provides a comprehensive fit to experimental data across various conditions.

## Contribution

It offers a quantitative analysis of magnetophonon resonances in graphene, highlighting the dominance of transverse acoustic phonons and connecting quantum and semiclassical models.

## Key findings

- Magnetophonon resonance amplitude is stronger for TA phonons than LA phonons.
- Electron-phonon coupling strengths fit resistivity data from 4-150 K.
- Semiclassical model explains the dependence of magneto-oscillation period on carrier density.

## Abstract

Recently observed magnetophonon resonances in the magnetoresistance of graphene are investigated using the Kubo formalism. This analysis provides a quantitative fit to the experimental data over a wide range of carrier densities. It demonstrates the predominance of carrier scattering by low energy transverse acoustic (TA) mode phonons: the magnetophonon resonance amplitude is significantly stronger for the TA modes than for the longitudinal acoustic (LA) modes. We demonstrate that the LA and TA phonon speeds and the electron-phonon coupling strengths determined from the magnetophonon resonance measurements also provide an excellent fit to the measured dependence of the resistivity at zero magnetic field over a temperature range of 4-150 K. A semiclassical description of magnetophonon resonance in graphene is shown to provide a simple physical explanation for the dependence of the magneto-oscillation period on carrier density. The correspondence between the quantum calculation and the semiclassical model is discussed.