New frontiers with quantum gases of polar molecules

The field of ultracold quantum matter has burgeoned over the last few decades, thanks to the growing capabilities for atomic systems to be probed and manipulated with exquisite control. Researchers can now precisely create and study quantum many-body states that are effectively isolated from the external environment. Much of the work in ultracold matter has focused on systems of alkali or alkaline-earth atoms, mainly due to their ease of cooling. Extending this precise control to molecules has seen rapidly increasing interest and activity, as molecules possess additional degrees of freedom that make them useful for tests of fundamental physics, studying ultracold chemistry and collisions, and engineering qualitatively new types of quantum phases and quantum many-body systems. Here, we review one particularly fruitful research direction: the creation and manipulation of ultracold bialkali molecules. The recent success in creating a quantum gas of polar molecules opens many exciting research opportunities.