Unit NANOMAGNETISM AND SPINTRONICS
- Course
- Physics
- Study-unit Code
- GP005936
- Location
- PERUGIA
- Curriculum
- Fisica della materia
- Teacher
- Gianluca Gubbiotti
- Teachers
-
- Gianluca Gubbiotti
- Hours
- 47 ore - Gianluca Gubbiotti
- CFU
- 6
- Course Regulation
- Coorte 2022
- Offered
- 2022/23
- Learning activities
- Affine/integrativa
- Area
- Attività formative affini o integrative
- Academic discipline
- FIS/03
- Type of study-unit
- Opzionale (Optional)
- Type of learning activities
- Attività formativa monodisciplinare
- Language of instruction
- Italian
- Contents
- Physics of magnetism and magnetic materials with low dimensionality. Fundamentals of spintronics and magnonics. Application to ICT devices.
- Reference texts
- Ibach-Luth, SOlid State Physics (Springer);
J. Stohr-H.C. Siegman, Magnetism (Springer);
D. Stancel - A. Prabhakar, Spin Waves (Springer)
S. M, Rezende Fundamentals Of Magnonics (Springer) - Educational objectives
- Understanding of the physics of magnetic materials, with particular reference to systems with nano dimensions. Knowledge of the main experimental investigation techniques and ability to carry out micromagnetic simulations. Application to ICT devices
- Prerequisites
- In order to fully understand the topics of this course it is necessary to be familiar with the basic topics of electromagnetism, physics of matter and quantum mechanics that are routinely taught in the mandatory courses of the three-year degree in physics.
- Teaching methods
- Lectures, also assisted by the projection of films and the execution of virtual experiments through simulations with micromagnetism software. Visit to nanomagnetism laboratories and realization of simple experiences related to the course content.
- Learning verification modality
- Oral exam at the end of the course, lasting about one hour. In the first part the student will be invited to expose a topic at will on which he or she has carried out an in-depth study, also drawing on the specialized literature of the sector. In the second part, the teacher will ask questions aimed at verifying the student's preparation on the program carried out.
- Extended program
- 1) Introduction to the course. Definition of relevant length and time scales. Overview of applications and theoretical approaches. Systems of units of measure. Recalls on atomic magnetism and spin-orbit interaction. Magnetism Orbital and spin magnetism. L-S and J-J coupling. Hund rules.
2) Classical theory of Diamagnetism and Paramagnetism of isolated atoms. Quantum correction. Pauli paramagnetsim and Landau diamagnetism for free electrons. Ferromagnetic behavior: classical Weiss theory, molecular field and magnetic domains.
3) Exchange interaction and its quantum origin. The helium atom. Ferromagnetism. Heisemberg Hamiltonian. Dependence of magnetization on temperature. Exchange interaction between free electrons. Band model of Ferromagnetism. Stoner's criterion. Spin waves in an exchange regime.
4) Quantum theory of electrical conduction, electron motion and transport phenomena. Boltzmann equation and relaxation time. Diffusion equation. Scattering in the bands. Spin-polarized currents and electrical conduction. Model of the two currents. Spin-dependent scattering. Spin accumulation. Exchange coupling between layers and giant magnetoresistance. Tunnel effect magnetoresistance and its applications. Spin valves and magnetic memories. Spin-Hall effect. Spintronic devices.
5) Magnetic Interactions. Magnetic Anisotropy. Magnetic Domains and Micromagnetism. Static Micromagnetic Simulations. Static and dynamic characterization techniques.
6) Spin Waves - Classic Approach. Susceptibility and Ferromagnetic Resonance. Self-oscillations in anisotropic ferromagnets. Magnetostatic spin waves and in the exchange regime. Spin waves in thin and multilayer films. Spin waves in confined systems.
7) Magnonic crystals. Manipulation and control of spin wave propagation. Wave guides. Excitation by inductive techniques. Nano-optics with spin waves. Magnonics