Magnetization dynamics down to zero field in dilute (Cd,Mn)Te quantum wells

TL;DR

This study investigates the magnetization dynamics in dilute (Cd,Mn)Te quantum wells, revealing ultra-fast decay at zero magnetic field driven by hyperfine interactions and strain, with hole gas effects influencing relaxation processes.

Contribution

It provides new insights into the zero-field magnetization dynamics and the roles of hyperfine interactions, strain, and hole gas in (Cd,Mn)Te quantum wells.

Findings

Magnetization decay at zero field is up to 1000 times faster than at 1 T.

Hyperfine interaction and strain are key factors in the fast decay.

Hole gas stabilizes Mn ions at zero field but accelerates decay under magnetic field.

Abstract

The evolution of the magnetization in (Cd,Mn)Te quantum wells after a short pulse of magnetic field was determined from the giant Zeeman shift of spectroscopic lines. The dynamics in absence of magnetic field was found to be up to three orders of magnitude faster than that at 1 T. Hyperfine interaction and strain are mainly responsible for the fast decay. The influence of a hole gas is clearly visible: at zero field anisotropic holes stabilize the system of Mn ions, while in a magnetic field of 1 T they are known to speed up the decay by opening an additional relaxation channel.