Abstract It is shown that strong coupling of Bose—Einstein condensates to an optical cavity can be realized experimentally. With an additional driven microwave field, we show that a highly nonlinear coupling among atoms in a Bose—Einstein condensate can be induced with the assistance of the cavity mode. With such interaction, we can investigate the generation of many body entangled states. In particularly, we show that multipartite entangled GHZ states can be obtained in such architecture with current available techniques.
We propose a scheme for generating many-atom maximal entanglement states in spin-1 Bose-Einstein condensates. By applying a far-off-resonate blue-detuned linear-polarized laser to the condensates, the hyperfine level
F=1,m=0 ground state and the hyperfine
F=0 excited state are conveniently coupled. Such a configuration is more efficient and provides a fast implementation of the maximally entangled GHZ state, using only half of the time that is required in single-atom Raman-transition-based schemes [You, Phys. Rev. Lett. 90, 030402 (2003)].
We propose a potentially practical scheme to entangle two distant atomic Bose-Einstein condensates (BEC), which is respectively in an optical cavity. Due to interaction between the cavity and the atomic BEC and the cavity decay, a linear polarized single-photon, which inputs the cavity, will rotate a certain angle after the input-output process, which is called Faraday rotation. Thanks to the faraday rotation of the photonic polarization, through detecting the output photonic polarization, we will entangle two distant Bose-Einstein condensates and generate entangled coherent states. Therefore, we provide a possible way to realize long-distance macroscopic quantum entanglement.