Cold Atomic Ensembles for Quantum Interfaces: New Interactions

Cold, trapped atomic ensembles present new opportunities for light-matter interfaces, including tomographic measurements and new interactions. The tensor polarizability can be exploited to produce interactions useful for spin squeezing, measurement of atom number, and quantum cloning of light into matter. We describe experiments in a cold ensemble of dipole-trapped 87Rb to produce spin squeezing by quantum non-demolition measurement.