Compact disc diffraction

TL;DR: In this paper, the authors developed and activated several interfaces necessary to efficiently deliver online teaching courses with the utmost speed, based on a common platform, Microsoft TEAMS, available to all teachers at Bologna University.

TL;DR: A series of experiments illustrate some of the more significant operational principles of the compact disc player and the physics of information density are explored through a set of experiments in optical storage.

TL;DR: In this paper, the authors proposed an alternative method using a laser ray box, which is also applied to a DVD and a Blu-ray disc, and demonstrated that it can be used to measure the track spacing on a CD using an incident laser beam normal to the surface or one at an oblique angle.

TL;DR: In this paper, the authors describe two pairs of experiments that may be of interest to teachers aiming to teach the wave nature of light and of particles to upper secondary school (or to college) students.

Abstract: Mathematical Introduction Acoustic Phonons Plasmons, Optical Phonons, and Polarization Waves Magnons Fermion Fields and the Hartree-Fock Approximation Many-body Techniques and the Electron Gas Polarons and the Electron-phonon Interaction Superconductivity Bloch Functions - General Properties Brillouin Zones and Crystal Symmetry Dynamics of Electrons in a Magnetic Field: de Haas-van Alphen Effect and Cyclotron Resonance Magnetoresistance Calculation of Energy Bands and Fermi Surfaces Semiconductor Crystals I: Energy Bands, Cyclotron Resonance, and Impurity States Semiconductor Crystals II: Optical Absorption and Excitons Electrodynamics of Metals Acoustic Attenuation in Metals Theory of Alloys Correlation Functions and Neutron Diffraction by Crystals Recoilless Emission Green's Functions - Application to Solid State Physics Appendix: Perturbation Theory and the Electron Gas Index.