Building a Platform for Spin Control based on a Cesium Atomic Ensemble with High Optical Depth

Atomic ensembles provide a versatile light-matter interface for the preparation of complex atomic quantum states. Light-matter interfaces can allow for the preparation of highly squeezed spin states and non-Gaussian states of many atoms based on measurement backaction for metrology and quantum information processing. We are developing a platform to prepare a large atomic ensemble of cold cesium atoms with high optical depth in free space, which will increase the light-matter interaction for efficient quantum state preparation based on measurement backaction. We investigate different methods for the optimization of the optical depth of the atomic ensemble including control of laser frequencies and powers, and compression of the atomic ensemble with time-varying magnetic fields in our magneto optical trap. We achieve an optical depth of 190 in our cesium ensemble in free space.