We study the quantum dynamics of an impurity-doped Bose–Einstein condensate (BEC) system. We show how to generate the macroscopic quantum superposition states (MQSSs) of the BEC by the use of projective measurements on impurity atoms. It is found that the nonclassicality of MQSSs can be manipulated by changing the number of the impurities and their interaction with the BEC. It is shown that the BEC matter-wave field exhibits a collapse and revival phenomenon which reveals the quantum nature of the BEC matter-wave field. We investigate the micro-macro entanglement between the impurities and the BEC, and find enhancement of the micro-macro entanglement induced by the initial quantum coherence of the impurity atoms.

中文翻译：

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掺杂杂质的玻色-爱因斯坦凝聚体的量子动力学

我们研究了掺杂杂质的玻色-爱因斯坦凝聚物（BEC）系统的量子动力学。我们展示了如何通过使用对杂质原子的射影测量来生成BEC的宏观量子叠加态（MQSSs）。发现可以通过改变杂质的数量及其与BEC的相互作用来控制MQSS的非经典性。结果表明，BEC物质波场表现出塌陷和复兴现象，揭示了BEC物质波场的量子性质。我们研究了杂质与BEC之间的微宏观纠缠，并发现了由杂质原子的初始量子相干引起的微宏观纠缠。