Magnetization Dynamics in Diluted Magnetic Semiconductor Heterostructures

Inhaltsverzeichnis (Table of Contents)

• Introduction
• II-VI diluted magnetic semiconductors
  • Crystal structure of (Cd,Mn)Te and (Zn, Mn)Se
  • Band structure of (Cd,Mn)Te and (Zn, Mn)Se
    • Band structure of zincblende semiconductors
    • Band structure of zincblende semiconductors containing manganese
  • Magnetic properties
    • Basic principles of magnetism
      • Larmor Diamagnetism
      • Paramagnetism
      • Heisenberg model
      • Ferromagnetism
      • Ferrimagnetism
      • Antiferromagnetism
    • Magnetic effects of free electrons
    • Magnetic properties of (Cd,Mn)Te and (Zn, Mn)Se without Mn-Mn-interaction
    • Exchange Interactions
      • sp-d exchange interaction
      • d-d exchange interaction
      • Magnetic properties of (Cd,Mn)Te and (Zn, Mn)Se with Mn-Mn interactions
      • Giant Zeeman-splitting
  • Quantum well heterostructures
    • Single-particle states in quantum wells
    • Spin-orbit-splitting in quantum wells
    • Heterostructures in magnetic field
    • Density of states in quantum wells
    • Selection rules and polarization degree in quantum wells
    • Parabolic and half-parabolic quantum wells
  • Excitons
    • Free exciton
    • Interaction of excitons with Mn²+-ions
    • Quasi-two-dimensional excitons in quantum wells
    • Quasi-two-dimensional excitons in magnetic field
    • Trions
• Magnetization dynamics
  • Spin and energy transfer
    • Coupled systems in diluted magnetic semiconductors
    • Theoretical formulation of spin and energy transfer
    • Manganese spin temperature in stationary condition
  • Mechanisms for spin relaxation
  • Spin lattice relaxation
  • Spin diffusion
• Experimental technique
  • Optical detection of Mn spin temperature
  • Heating of the Mn spin system
  • Time-resolved measurements
  • Experimental setup
• Interaction between carriers and Mn-spin system
• Spin-lattice relaxation
• Control of spin-lattice relaxation
• Summary

Zielsetzung und Themenschwerpunkte (Objectives and Key Themes)

This dissertation investigates the magnetization dynamics in diluted magnetic semiconductor heterostructures. The work aims to understand the mechanisms governing spin and energy transfer between charge carriers and the Mn spin system, and to explore possibilities for controlling spin-lattice relaxation.

• Spin and energy transfer mechanisms in diluted magnetic semiconductors
• Spin relaxation mechanisms in these materials
• Control of spin-lattice relaxation through various techniques
• Characterisation of II-VI diluted magnetic semiconductors
• Experimental techniques for investigating magnetization dynamics

Zusammenfassung der Kapitel (Chapter Summaries)

The introduction provides background information on the subject. Chapter 1 details the properties of II-VI diluted magnetic semiconductors, including their crystal structure, band structure, and magnetic properties. Chapter 2 discusses magnetization dynamics, focusing on spin and energy transfer mechanisms and spin relaxation processes. Chapter 3 describes the experimental techniques used in the study. Chapter 4 analyzes the interaction between charge carriers and the Mn spin system. Chapters 5 and 6 explore spin-lattice relaxation and methods for its control.

Schlüsselwörter (Keywords)

Diluted magnetic semiconductors, magnetization dynamics, spin relaxation, spin-lattice relaxation, spin transfer, energy transfer, II-VI semiconductors, quantum well heterostructures, experimental techniques, Mn spin system.