Ab initio dipolar electron-phonon interactions in two-dimensional materials

TL;DR

This paper introduces an ab initio formalism for dipolar electron-phonon interactions in 2D materials, highlighting the importance of out-of-plane dipoles and improving the accuracy of carrier mobility predictions.

Contribution

The authors develop a new ab initio approach for dipolar EPI in 2D materials, accounting for out-of-plane dipoles, which enhances the accuracy of electron-phonon interaction modeling.

Findings

Out-of-plane dipoles significantly affect 2D EPI.

The formalism improves carrier mobility predictions.

The traditional Fr"ohlich model is insufficient for 2D materials.

Abstract

We develop an ab initio formalism for dipolar electron-phonon interactions (EPI) in two-dimensional (2D) materials. Unlike purely longitudinal Fr\"ohlich model, we show that the out-of-plane dipoles also contribute to the long-wavelength non-analytical behavior of EPI. And the 2D dipolar EPI plays an important role not only in the typical polar material MoS$_2$, but also in graphane and fluorinated graphene. By incorporating this formalism into Wannier-Fourier interpolation, we enable accurate EPI calculations for 2D materials and subsequent intrinsic carrier mobility prediction. The results show that Fr\"ohlich model is inadequate for 2D materials and correct long-wavelength interaction must be included for the reliable prediction.