Photon Blockades in an Optomechanical Cavity with a Bose-Einstein Condensate in the Strong Coupling Regime

A proposal is made on how to manipulate photon blockades (PBs) and photon-induced tunneling (PIT) in an optomechanical cavity with a Bose-Einstein Condensate. It is shown that the single-photon blockade (1PB) can emerge with appropriate scattering strength between atoms. Further, by tuning interatomic scattering strength, the switch between 1PB and PIT at the fixed optical detuning can be realized in interatomic repulsion or attraction conditions. The enhancement of 1PB can also be achieved. The scattering control of PBs can be understood from the perspective of the anharmonicity of the energy levels modulated by the interatomic collision. Such a system can be equivalent to a conventional optomechanical system plus an interatomic scattering term. It is found that although there are no PBs in the conventional optomechanical system, in the BEC optomechanical system (BECOMS), PBs can occur at the fixed optical detuning. Moreover, the BECOMS can exhibit stronger 1PB under the same optomechanical coupling intensity. Due to the advantages of intrinsic strong optomechanical nonlinearity and the negligible thermal noise of the mechanical environment, BECOMS is promising for experimental realization of PBs. The results open new possibilities for manipulating few-photon states in quantum regime in cavity optomechanics with a Bose-Einstein Condensate.