A gas of ultracold polar molecules at high phase-space density

Ultracold polar molecules are needed for a wide range of new applications in physics and physical chemistry. They can be used to test fundamental physics, to study ultracold chemistry, to investigate dipolar quantum gases, to process quantum information, and to simulate the behaviour of strongly-interacting many-body quantum systems. All these applications require molecular gases at high phase-space density - meaning very low temperature and sufficiently high density. Recently, laser cooling has been applied to molecules, producing trapped samples of molecules at micro-kelvin temperatures. However, the phase-space density remains orders of magnitude below that needed for many applications. The goal of this project is to increase the phase-space density, aiming for a quantum degenerate gas of molecules. First, a method to compress the gas will be explored, in order to increase its density. Then, the molecules will be co-trapped with ultracold atoms, and methods will be explored to enhance elastic collisions while inhibiting inelastic and reactive collisions. With the collisions under control, evaporative cooling of the atoms, together with sympathetic cooling between atoms and molecules, will drive up the phase-space density.