# Intervalley Polaron in Atomically Thin Transition Metal Dichalcogenides

## TL;DR

This paper theoretically investigates how electron-phonon interactions cause intervalley coupling in monolayer transition-metal dichalcogenides, affecting electronic properties like band splitting and effective mass, with implications for experimental measurements.

## Contribution

It introduces a theoretical model for intervalley polaron coupling in TMD monolayers and predicts its effects on electronic band structure and magneto-phonon resonance.

## Key findings

- Renormalization of conduction band spin splitting
- Increase in electron effective masses
- Prediction of inter-valley magneto-phonon resonance

## Abstract

We study theoretically intervalley coupling in transition-metal dichalcogenide monolayers due to electron interaction with short-wavelength phonons. We demonstrate that this intervalley polaron coupling results in (i) a renormalization of the conduction band spin splitting and (ii) an increase of the electron effective masses. We also calculate the renormalization of the cyclotron energy and the Landau level splitting in the presence of an external magnetic field. An inter-valley magneto-phonon resonance is uncovered. Similar, but much weaker effects are also expected for the valence band holes. These results might help to resolve the discrepancy between ab initio values of the electron effective masses and the ones deduced from magneto-transport measurements.