Thin films: Magnetism and Superconductivity
The course presents two important phenomena that are strongly influenced by dimensionality: magnetic order and superconductivity. Both subjects are presented at a general level in solids and discussed for their modifications in thin films, at interfaces and in solids characterized by an intrinsic reduced dimensional (2D or 1D) structure. Some experimental technique for the exploration of relevant magnetic and electronic properties are also described. The aim is to broaden the knowledge of important ordering phenomena in solids and to underline how dimensionality may alter them.
Magnetism of isolated magnetic moments
Phenomenology: recalling diamagnetism, paramagnetism and atomic moments.
Crystal field: origin of CF, quenching of orbital moments, Jahn-Teller effect.
Magnetic order and magnetic structures.
Heisenberg and Ising models.
Magnetism in metals
Pauli paramagnetism, Landau diamagnetism, Stoner model, RKKY interaction.
Excitations in magnetic systems.
Spin waves, Stoner excitations
Magnetism at low dimensionality.
Spin chains and spin ladders, 2 dimensional magnets, thin films.
Superconductivity: phenomenology, London equations, Josephson effect, BCS theory, Cuprate superconductors (also as an example of 2D antiferromagnets).
Magnetic resonances, Mössbauer spectroscopy.
Elastic and inelastic scattering for magnetic structure and magnetic excitations.
S. Blundell “Magnetismm in condensed matter”, Oxford University Press
Ashcroft-Mermin “Solid State Physics”, Saunders College.
Bachelor courses on Quantum physics, Structure of matter and Mathematics. Master course in Solid state physics.