The project runs for 5 years and allows Jan Arlt to support two PhD students. A description of the project is given below.

All aspects of the world around us are governed by the microscopic quantum properties of its constituents, the individual atoms and molecules. However, it is generally not possible to solve the quantum mechanical equations which describe the behavior of this vast number of particles. In response to this problem, Nobel laureate R. Feynman proposed in 1982 to use nature itself to learn more about quantum systems: he suggested that a wellcontrolled quantum system could be used to mimic the quantum properties of a system we wish to investigate. This method is called Quantum Simulation.

Ultracold quantum gases provide such a quantum simulator for many important systems in physics, since they can be controlled with unprecedented flexibility and accuracy.

Within this project, we will tackle two important problems by using quantum gases in combination with a non-destructive detection technique (so-called Faraday detection) as a quantum simulator. In the first instance, we will investigate the fluctuations which occur when a quantum gas is formed. This is important for understanding many technically relevant systems such as superconductors or superfluids. Secondly, we will investigate the dynamics of an impurity, a so-called polaron, in a dual species quantum gas. Since these polarons are ubiquitous, e.g., in solid state systems, their understanding is equally important.

The impact of this project thus extends well beyond the field of ultracold quantum gases and will make significant contributions to the understanding and application of important condensed matter systems.