Doped graphene as tunable electron-phonon coupling material

TL;DR

This paper demonstrates a method to tune electron-phonon coupling in graphene via doping, affecting Raman spectral features and enabling the development of tunable electronic devices.

Contribution

It reveals doping-dependent electron-phonon coupling in graphene influenced by electron-electron correlations, which was not captured in previous mean-field models.

Findings

EPC at the K point depends strongly on doping levels.

Doping influences the Raman D and 2D line dispersion.

Doping enables tunable electronic device design.

Abstract

We present a new way to tune the electron-phonon coupling (EPC) in graphene by changing the deformation potential with electron/hole doping. We show the EPC for highest optical branch at the high symmetry point K, acquires a strong dependency on the doping level due to electron-electron correlation not accounted in mean-field approaches. Such a dependency influences the dispersion (with respect to the laser energy) of the Raman D and 2D lines and the splitting of the 2D peak in multi-layer graphene. Finally this doping dependence opens the possibility to construct tunable electronic devices through the external control of the EPC.