# Controlled coherent-coupling and dynamics of exciton complexes in a MoSe$_2$ monolayer

## TL;DR

This study demonstrates how gate bias can tune the coherent dynamics and coupling of exciton complexes in a MoSe₂ monolayer, advancing understanding for quantum optoelectronic applications.

## Contribution

It introduces a method to control exciton coherence and coupling in MoSe₂ monolayers using gate bias, with direct experimental evidence from ultrafast spectroscopy.

## Key findings

- Gate bias tunes exciton linewidth and decay.
- Bias controls coherent coupling between exciton complexes.
- Ultrafast spectroscopy reveals dynamic control of excitonic interactions.

## Abstract

Quantifying and controlling the coherent dynamics and couplings of optically active excitations in solids is of paramount importance in fundamental research in condensed matter optics and for their prospective optoelectronic applications in quantum technologies. Here, we perform ultrafast coherent nonlinear spectroscopy of a charge-tunable MoSe$_2$ monolayer. The experiments show that the homogeneous and inhomogeneous line width and the population decay of exciton complexes hosted by this material can be directly tuned by an applied gate bias, which governs the Fermi level and therefore the free carrier density. By performing two-dimensional spectroscopy, we also show that the same bias-tuning approach permits us to control the coherent coupling strength between charged and neutral exciton complexes.