Valley pseudospin relaxation of charged excitons in monolayer MoTe$_2$

TL;DR

This study investigates how magnetic fields affect valley pseudospin relaxation in charged excitons within monolayer MoTe$_2$, revealing complexities in g-factor determination and valley dynamics through time-resolved photoluminescence.

Contribution

It provides a detailed analysis of valley pseudospin relaxation mechanisms in monolayer MoTe$_2$ using both time-integrated and time-resolved photoluminescence measurements.

Findings

Time-resolved experiments show different timescales than time-integrated data.

The g-factor deduced from time-integrated data is not supported by time-resolved measurements.

Magnetic field influences valley polarization and exciton dynamics in MoTe$_2$.

Abstract

Zeeman effect induced by the magnetic field introduces a splitting between the two valleys at K$^+$ and K$^-$ points of the Brillouin zone in monolayer semiconducting transition metal dichalcogenides. In consequence, the photoluminescence signal exhibits a field dependent degree of circular polarization. We present a comprehensive study of this effect in the case of a trion in monolayer MoTe$_2$, showing that although time integrated data allows us to deduce a g-factor of the trion state, such an analysis cannot be substantiated by the timescales revealed in the time-resolved experiments.