Theoretical Studies Of Dynamical Generation Of Phase-Squeezed State And Linear Atom Interferometer

As the development of laser cooling technology, the study and application of super cold atom has been attracted much attentions. In particular, atom interferometer is stand out from its many kinds of applications, In the Precision measurement, Contrast with optic interferometer, atom interferometer has particular advantage. The cold atom enjoys good maneuverability, we can control its quantum state; and the cold atom has low speed, so the time of interference will be longer, we can get better interference. Cold atom interferometer has much better sensitivity and accuracy.For the convenience of computation, we research a linear atom interferometer with symmetric input state. We focus on its sensitivity. Phase-squeezed state (B-W state) proposed by Berry and Wiseman exhibits the best sensitivity approaching to the Heisenberg limit, In this paper, we study the character of B-W state, and similar with it, we find this kind of state, which shows the squeezing along spin operator Sy and the anti-squeezing along SZ. Our results show that this generated phase-squeezed state is not perfect as B-W state, but it can achieve sub-shot-noise-limited.We confined the atomic Bose-Einstein condensates in a symmetric double-well potential, we can use direct indirect two method to prepare the phase-squeezed state. The direct method is that we take the coherent sin state into a large coupling ratio environment, for a period of time we can get the phase-squeezed state; the indirect method is that we can get the phase-squeezed state for spin the number-squeezed state.