Some Phenomena in Many-Particle Systems Far from Equilibrium.

É. N. Rumanov

É. N. Rumanov

É. N. Rumanov

Paul A. Fleury

Transformations among many of the diverse states of matter arise from microscopic interactions involving very many (approximately 10(23)) constituent particles and result in dramatic changes in macroscopic properties. The values of some physical parameters vanish, while others approach infinity. These changes and their evolution are strikingly similar in systems as apparently different as liquids, magnets, superconductors, ferroelectrics, and liquid crystals, which suggests that there is an underlying unity to phase transition phenomena. The basis and extent of this unity are reviewed for many-body systems in equilibrium, and analogies with instability phenomena in systems far from equilibrium (such as lasers, fluid flows, and avalanche electronic devices) are pointed out.

I. I. Ivanchik

Simone A. Hamerla

In the last years the impressive progress on the experimental side led to a variety of new experiments allowing to address systems out of equilibrium. In this way the behavior of such systems far from equilibrium is no longer a purely theoretical issue but indeed observable. New experimental techniques, like particles trapped in optical lattices, render a realization of quantum systems with nearly arbitrary system parameters possible. Thus a study of interaction quenches where the interaction between the particles is suddenly switched on is possible. As these quenches take the system far from equilibrium the dynamics is governed by highly excited states, which leads to totally new fascinating phenomena. In this work interaction quenches in fermionic Hubbard models are studied in one and two dimensions allowing to study the influence of integrability on the dynamics of the system. Besides, the influence of doping on the time evolution of the system is calculated.