# Dynamics of exciton magnetic polarons in CdMnSe/CdMgSe quantum wells: the effect of self-localization

## TL;DR

This study investigates the formation and dynamics of exciton magnetic polarons in CdMnSe/CdMgSe quantum wells, revealing a longer formation time due to strong self-localization effects that influence exciton properties.

## Contribution

It provides new insights into EMP formation time and self-localization effects in diluted-magnetic-semiconductor quantum wells, supported by time-resolved photoluminescence data.

## Key findings

- EMP energy of 14 meV consistent with measurements
- Polaron formation time of 500 ps longer than previous reports
- Self-localization causes wavefunction squeezing and affects exciton lifetime

## Abstract

We study the exciton magnetic polaron (EMP) formation in (Cd,Mn)Se/(Cd,Mg)Se diluted-magnetic-semiconductor quantum wells using time-resolved photoluminescence (PL). The magnetic field and temperature dependencies of this dynamics allow us to separate the non-magnetic and magnetic contributions to the exciton localization. We deduce the EMP energy of 14 meV, which is in agreement with time-integrated measurements based on selective excitation and the magnetic field dependence of the PL circular polarization degree. The polaron formation time of 500 ps is significantly longer than the corresponding values reported earlier. We propose that this behavior is related to strong self-localization of the EMP, accompanied with a squeezing of the heavy-hole envelope wavefunction. This conclusion is also supported by the decrease of the exciton lifetime from 600 ps to 200 - 400 ps with increasing magnetic field and temperature.