Nanomagnetism and spintronics UGA - WPMNNSP7

Objectif(s)

After some general reminders on magnetism, we will focus on the effects on magnetism and magnetic domains of down-scaling and going to thin films and nanostructures/nanodots. We will in particular study the effects of dipolar interactions and how to calculate them. We will then discuss about magnetization reversal in quasistatic conditions, either in macrospin or via domain wall motion, in particular in thin films and nanostructures. In addition to this quasistatic description, we will study magnetization dynamics occurring at short timescales (ns) using the Landau-Lifshitz-Gilbert equation. Ferromagnetic resonance, precessional switching/domain wall motion and damping will be derived here. Finally, after studying the basics of spin dependent transport, from spin-dependent electronic scattering to spin-orbit coupling and spin accumulation, we will describe state-of-the-art spintronics applications and their perspectives.

Contenu(s)

Chapter 1: Setting the ground of nanomagnetism

• Magnetic fields and materials
• Units in magnetism
• Magnetic energies and characteristic quantities
• Dipolar interactions
• Magnetic domain walls
• Magnetometry, magnetic imaging

Chapter 2: Magnetism, domains at low dimensions

• Magnetic ordering in low dimensions
• Magnetic anisotropy in low dimensions
• Domains, domain walls in thin films and in nanostructures

Chapter 3: Magnetization reversal

• Macrospin (Stoner-Wolhfarth model, dynamic effects, superparamagnetic regime)
• Magnetization reversal in nanostructures and in extended systems (near single domain, domain wall motion)

Chapter 4: Precessional dynamics of magnetization

• Ferromagnetic resonance and Landau-Lifshitz-Gilbert equation
• Precessionnal switching of macrospin by magnetic field
• Precessional motion of domain wall by magnetic field

Chapter 5: Magnetotransport-Spintronics

• Electronic and spin transport (Anisotropic magneto-resistance AMR, Current-in-plane Giant magnetoresistance CIP-GMR)
• Spin accumulation (Current perpendicular to plane CPP-GMR)
• Transfer of angular momentum (Spin transfer torque)
• Spintronics applications and perspectives (Current and future)

Magnetism M1
Electromagnetism
Solid state physics M1