We plan to experimentally develop a quantum tweezer to extract a certain number of atoms from a Bose-Einstein condensation (BEC) cloud and to investigate the possibility to detect with certainty freely propagating atoms on the single-atom level. On this basis we are going to explore the feasibility to generate and detect multi-particle entanglement by exploiting atom-atom collision and linear optics.

In my project, we start with a trapped Bose-Einstein condensation (BEC) ensemble. From which, we can extract a definite number of atoms at will with a quantum tweezer, which may be generated by a focus beam of red-detuned laser light. After having successfully extracted two atoms, the quantum tweezer is switched off non-adiabatically, which correspond s to a decay of a two-atom system, so that the two atoms will freely propagate along correlated directions. That is to say, the freely propagating atoms will be entangled in the momentum space.

In order to verify the successful generation of entanglement, we will develop an imaging system to detect the single atom with nearly 100% certainty. We shall then carry out observation of entanglement by combining the atoms along different ways at their corresponding 50:50 atomic beam splitters. Depending on the outcome of these experiments we will assess the quality of two-atom entanglement such that, we know whether it can be used to perform both the fundamental tests of quantum mechanics versus local realism and the quantum information processing.

The possible next step will be investigating the generation of multi-atom entanglement. Since single atom detection efficiency can reach to 100%, an experimental generalization of linear optics quantum information processing to the atomic domain would open up the new perspective for the future quantum information processing.