Direct measurement of the three dimensional magnetization vector trajectory in GaMnAs by a magneto-optical pump-and-probe method

TL;DR

This paper presents a novel magneto-optical pump-and-probe technique for directly measuring the three-dimensional magnetization vector trajectory in GaMnAs, enabling detailed analysis without numerical modeling.

Contribution

The study introduces a new experimental method using polarization-dependent magneto-optical effects to accurately track magnetization dynamics in three dimensions.

Findings

Successfully measured 3D magnetization trajectories in GaMnAs.

Disentangled in-plane and out-of-plane magnetization motions.

Sensitive enough to detect small angle excitations.

Abstract

We report on a quantitative experimental determination of the three-dimensional magnetization vector trajectory in GaMnAs by means of the static and time-resolved pump-and-probe magneto-optical measurements. The experiments are performed in a normal incidence geometry and the time evolution of the magnetization vector is obtained without any numerical modeling of magnetization dynamics. Our experimental method utilizes different polarization dependences of the polar Kerr effect and magnetic linear dichroism to disentangle the pump-induced out-of-plane and in-plane motions of magnetization, respectively. We demonstrate that the method is sensitive enough to allow for the determination of small angle excitations of the magnetization in GaMnAs. The method is readily applicable to other magnetic materials with sufficiently strong circular and linear magneto-optical effects.