双模SU(2)相干态场与一个V型三能级原子共振相互作用系统的光子统计性质研究

Statistic Properties of Photon in the System of A Two-mode SU(2)Coherent Field Resonantly Interacting with A Three-Level V-Type Atom

采用全量子理论和数值计算方法,研究了初始处于SU(2)相干态的双模腔场与一个V型三能级原子共振相互作用系统的光子统计性质,讨论了在没有对原子进行态选择测量、直接对原子进行态选择测量和应用经典微波场并对原子进行态选择测量的3种情况下2个腔模总光子数M、配分参量S和耦合系数对光子统计性质的影响。结果表明,直接对原子进行态选择测量,a模的亚Poisson统计分布的平均程度变深;减小配分参量S,a模光子的亚泊松统计分布的平均程度变浅,而b模变深;对原子进行态选择测量,违背Cauchy-Schwartz不等式;两模间的反相关特征保持不变,增加总光子数M或直接对原子进行态选择测量,反相关平均程度变浅。

Statistic properties of photon in the system of a two-mode field initially in a coherent state resonantly interacting with a three-level V-type atom are investigated by means of the quantum theory and numerical calculations.The dependence of the statistic properties of photon on the total photon number of the two-mode,the partition parameter and the coupling constant are discussed for three cases:①no state-selective atomic measurement;②direct state-selective atomic measurement;③state-selective atomic measurement after the application of a classical field.The results indicate that when the direct state-selective measurement is performed on the atom,the average intensity of the sub-poisson statistic distribution of mode a is enhanced;when the partition parameter is decreased,the average intensity of the sub-poisson statistic distribution of mode a is reduced and that of mode b is enhanced;when the state-selective mesurement is performed on the atom,the Cauchy-Schwarz inequality is violated;when the total photon number of the two modes is increased or the direct state-selective measurement is performed on the atom,the anti-correlation character between the two modes is preserved,but the average intensity of the anti-correlation is reduced.