Quantum dynamics of low-dimensional atomic Fermi gases

点击翻译按钮获取中文摘要

Since the discovery of superconductivity a century ago, correlated quantum many-body systems have evolved from a scientific peculiarity to key components of commercially available devices such as sensors or medical instrumentation. Yet, both realizing and understanding collective states of strongly correlated matter remain major scientific challenges. Among the unresolved puzzles, low-dimensional fermionic quantum systems play a pivotal role, because a number of intriguing effects such as high-Tc superconductivity in the cuprates, the quantum Hall effect, and Luttinger liquid behaviour are intimately linked to reduced dimensionality. Of particular current interest is the non-equilibrium dynamics of these many-body systems. The understanding of emergent states far from equilibrium constitutes one of the grand challenges in Physics and is of great importance for applications, e.g. for the transport of energy or information in the next generation of quantum devices and in quantum computing. A major difficulty to be overcome is that dynamical experiments in the solid state often are overwhelmed by the strong coupling to the environment and the resulting decoherence destroys the genuine quantum dynamics already on short time scales. In recent years, it has become possible to assemble strongly correlated quantum many-body systems in a bottom-up approach using ultracold atomic quantum gases. This novel approach has created the purest and most widely tunable "materials", in which quantum many-body physics can be studied. They are considered ideal candidates for both unravelling the mysteries of observed, but not yet understood, effects in the solid state and for realizing completely new quantum phases, very much in the sense of Feynman's concept of a "quantum simulator". Perhaps most importantly, cold atomic gases provide an ideal testing ground for non-equilibrium evolution because the tuneability is very rapid compared to the typical energy/time scales of the system and the dynamics remains coherent for long times by virtue of their weak coupling to the environment.