# IMPRS Course Archive 2017

*competition*between localization of electrons in solids due to Coulomb repulsion and delocalization in energy bands due to kinetic energy lowering. Invented in the early 1960s to descibe magnetism in transition-metal monoxides, it has been generalized and applied to a host of problems in condensed matter including heavy fermions or high-temperature superconductors. Despite its apparent simplicity it shows complicated phase diagrams that depend on dimensionality and lattice coordination as well as electronic filling, with only few exact solutions in limiting cases known to this date. [more]

^{-15}s) and even attosecond (as, 10

^{-18}s) order. With such sources, one can observe chemical reactions, physical and biological phenomena in real time. During the lectures, I will give a short overview of NLO. I will discuss the main physical phenomena (second harmonic generation, optical parametric amplification, difference and sum frequency generation, white light generation, third harmonic generation, high harmonic generation…) and some of their applications, and conclude with the newest trends of research like coherent pulse synthesis. [more]