We propose an alternative scheme for generation of atomic Schrödinger cat states in an optical cavity. In the scheme the atoms are always populated in the two ground states and the cavity remains in the vacuum state. Therefore, the scheme is insensitive to the atomic spontaneous emission and cavity decay. The scheme may be generalized to the deterministic generation of entangled coherent states for two atomic samples. In contrast with the previously proposed schemes of [Commun. Theor. Phys. 40 (2003) 103 and Chin. Phys. B 18 (2009) 1045], the required interaction time in our scheme is greatly shortened and thus the decoherence can be effectively suppressed.
A scheme is proposed for the generation of superpositions of multi-mode coherent states, i.e. multi-mode Schrödinger cat states. In the scheme a -type three-level atom is sent through many cavities filled with coherent fields. The whole system is entangled via the Raman atom-field interaction. Then the detection of the atom leaves the cavity system in a multi-mode cat state. Under certain conditions, such a cat state is identical to a Greenberger-Horne-Zeilinger state and thus can be used to test local realistic theories.
An efficient scheme is proposed for the generation of atomic Schrodinger cat states in an optical cavity. Inthe scheme N three-level atoms are loaded in the optical cavity. Raman coupling of two ground states is achieved via alaser field and the cavity mode. The cavity mode is always in the vacuum state and the atoms have no probability ofbeing populated in the excited state. Thus, the scheme is insensitive to both the cavity decay and spontaneous emission. Keywords：atomic Schrodinger cat state, optical cavity, three-level atom