Experimental test of Bohr's complementarity principle with single neutral atoms

An experimental test of the quantum complementarity principle based on single neutral atoms trapped in a blue detuned bottle trap was here performed. A Ramsey interferometer was used to assess the wavelike behavior or particlelike behavior with second pi/2 rotation on or off. The wavelike behavior or particlelike behavior is characterized by the visibility V of the interference or the predictability P of which-path information, respectively. The measured results fulfill the complementarity relation P-2 + V-2 <= 1. Imbalance losses were deliberately introduced to the system and we find the complementarity relation is then formally "violated." All the experimental results can be completely explained theoretically by quantum mechanics without considering the interference between wave and particle behaviors. This observation complements existing information concerning Bohr's complementarity principle based on wave-particle duality of a massive quantum system.