Λ型原子与单模光场的非共振作用制备四光子相干态

Generation of Four-Photon Coherent States Through Far-Off Non-Resonant Interaction of Λ-Type Atom with Cavity Field of Single Mode

根据简并Λ型三能级原子与单模光场的改进型有效哈密顿量 ,通过矩阵形式法推导出原子光场系统的波函数 ,提出利用简并Λ型三能级原子与单模光场的远离共振相互作用制备四光子相干态的有效方案。并且证明按照同样的方法不能制备出四成分以上的相干叠加态 ,即当在腔中注入的第三个原子的速度与第二个原子的速度相等时 。

Based on the modified effective Hamiltonian for the atom field system, the wave function of the system is derived by means of matrix forms. A feasible scheme is presented to generate the four photon coherent states via far off resonant interaction of a degenerate Λ type three level atom with coherent state cavity field. It is also proved that the superposition states of four photon coherent states with more than four component cannot be generated by using the above same method. That is, the four photon coherent states can remain unchanged in the cavity when the third atom with the same velocity as the second atom is injected into the cavity.