CHAPTER 11: Controlling a Quantum Gas of Polar Molecules in an Optical Lattice

The production of molecules from dual-species atomic quantum gases has enabled experiments that employ molecules at nanokelvin temperatures. As a result, every degree of freedom of these molecules is in a well-defined quantum state and exquisitely controlled. These ultracold molecules open a new world of precision quantum chemistry in which quantum statistics, quantum partial waves, and even many-body correlations can play important roles. Moreover, to investigate the strongly correlated physics of many interacting molecular dipoles, we can mitigate chemical reactions, which would otherwise lead to loss of molecules from the desired quantum state, by controlling the dimensionality of the system using optical lattices formed by interfering laser fields. In a full three-dimensional optical lattice, chemical processes can be turned on or off by tuning the lattice depth, which allows us to configure an array of long-range interacting quantum systems with rich internal structure. Such a system represents an excellent platform for gaining fundamental insights to complex materials based on quantum simulations and also for quantum information processing in the future.