Exploring cavity-mediated long-range interactions in a quantum gas

Creating quantum gases with long-range atom-atom interactions is a vibrant area of current research, possibly leading to the observation of novel quantum phases and phase transitions. In our approach, we couple the external degree of freedom of a Bose-Einstein condensate to the vacuum mode of a high-finesse optical cavity using a non-resonant standing-wave transverse pump beam. This gives rise to a driven-dissipative system with cavity-mediated atom-atom interactions of global range, which are tunable both in magnitude and sign.