Ultracold neutral plasmas and Rydberg gases

We present two different theoretical approaches for the simulation of ultracold plasmas and Rydberg gases, namely a simple kinetic model including an approximate treatment of ionic correlations on the one hand and a hybrid molecular dynamics (MD) approach treating the electrons as a fluid but ions and atoms on a full MD level on the other hand. The simple kinetic model can be used in situations where the number of particles is so large that it prohibits an MD simulation, and, maybe even more importantly, it gives additional insight into the dynamics beyond that possible on the basis of MD simulations by providing simple evolution equations for the macroscopic parameters describing the state of the system. On the other hand, the MD approach provides a powerful method for the study of spatially resolved quantities, and it permits the study of scenarios where the ions are so strongly coupled that Coulomb crystallization occurs, which cannot be described by the kinetic model.