The way in which atoms vibrate around their equilibrium positions as a function of temperature is of fundamental importance for a broad range of physical properties of solids, for example thermal expansion, specific heat, thermal conductivity, and superconductivity. In systems with magnetic order, there also exists collective motion of the magnetic moments, in addition to the above-mentioned lattice vibrations. Although worth being investigated individually, the atomic magnetic moments and the lattice degrees of freedom are always coupled via the electron subsystem. These couplings determine, for instance, how fast it is possible to change the magnetic state of a material, and how relaxation of the phonon and the electron subsystem proceeds after excitation with ultra-short laser pulses. Most of the different coupling mechanisms between the spin, lattice, and electronic degrees are still unexplored.
In this course, I will give an overview on couplings between spins, phonons, and electrons in both the adiabatic and the nonadiabatic limit. The lectures will cover a broad range of theoretical models and methods as well as some overview on experimental techniques. Theoretical concepts of the course can be directly applied during hands-on sessions.
Time & Location
Jul 11, 2022 - Jul 12, 2022
MLU Halle-Wittenberg - Institute of Physics