|SCIENTIFIC DISCIPLINARY SECTOR||FIS/03|
Nanoscale solid state devices are at the basis of current technology. This course will describe the physical basis of their working principles.
The course aims at the understanding of the major concepts and methodologies used in solid state phyiscs to investigate perfect crystals and at stimulating the crytical analysis of their properites in the less ideal conditions.which are realized in practice. The course will also describe how to modify materials to obtain novel properties.The different approximations and schemaitizations will be highlighted which allow solving complicated problems with clever simplifications.
Frontal lectures on solid state concepts and on the principla modern experimental techniques for the investigation of solids (40 ore)
Practical demostrations of the experimental techniques (12 ore)
Exam: The student will be asked to expose an topic of own choice. A second topic will be eventually chosen by the jury components.
1) Condensed matter states: liquids, amorphous solids, crystals. Lattice structure and chemical bonds. Lattice symmetry and examples of lattice structure for different materials. Stable and metastable structures, minimum of free energy of a system. Internal pressure of a solid due to the electron gas. Description of the solid in term of lattice planes and reciprocal space. Brillouin zones. Experimental methods to determine the crystallographic structure. Ewald sphere construction. Structure and form factors. Cristals and quasicrystals.
2) Electrons in solids: non interacting particles, jellium model, Hamiltonian of a system, Born Oppenheimer approximation, Hartree and Hartree Fock approximations, Density Functional Theory and ab initio calculations.
3) The crystal lattice:tight binding approximation pseudopotentials, Brillouin zones and electronic band structure. Fermi level in the different zones. Concepts of quasiparticle and of wavevector. Examples of band structure for Al and Ag. Density of states. Fermi level.
4) Probe particles. Neutron scattering: sources, waveguides, lenses, monochromators, polarizers, detectors, Coherent and incoherent scattering. Elastic and inelastic scattering.
5) Lattice dynamics, Phonon spectrum. Acoustic and optical phonons. Investigation of the phonon spectrum by inelastic scattering of neutrons and X-Rays.
6) Electrodynamics of a continuum. Response function to external electric fields, Dielectric function. Models for the dielectric response and its dependence on frequency and wavevector. High and low frequency limits for metals and non metals. Plasma frequency and relationship with optical properties Real and imaginary part of the dielectric function and interband transitions. Surface plasmons Mie resonance in nanoparticles. Negative refraction index and optical metamaterials. Artificial lattices for photonics, and phononics and heterostructures. Plasmonics.
7) Magnetic properties. Heisenberg model. Spin waves.
8) Interaction of light with matter. Photoemission, multipole plasmons. Appearence spectroscopies, EXAFS e NEXAFS. Opportunities given by synchtrotron radiation.
9) Defect in solids. Inerstitials and vacancies, diffusion of defects, dopants in semiconductors. Localized electronic states. Effects on mechanical properties
10) Surfaces and bidimensional solids. Why are their properties interesting and different from those of three dimensional solids.
Atomic and Electronic Structure of Solids
Cambridge University Press
Additional material given by the teacher
Office hours: For explanations the students will be received on Thursday mornings in the office of the teacher
MARIO AGOSTINO ROCCA (President)
GIOVANNI CARRARO (President Substitute)
GIANANGELO BRACCO (Substitute)
according to schedule. The course will be given in the first semester
All class schedules are posted on the EasyAcademy portal.