中文摘要：

里德伯原子的Stark效应在偶极偶极相互作用、量子信息和量子调控等方面具有潜在的应用前景．本文首先根据零场时镓原子的能级数据，通过非线性拟合方法获得了镓原子各态的量子亏损，仔细分析了量子亏损随主量子数的变化特征；然后利用Numerov算法计算了镓原子的径向波函数；最后采用矩阵对角化方法，数值计算了镓原子高里德伯态在场强范围F=0-3000V．cm^-1时n=7和n=18附近的Stark能级结构．结果显示在主量子数n=7多重态以上的能级结构中，（n＋1）P态的能级接近并大于nD态的能级，在n=7多重态以下的能级结构中，（n＋1）P态的能级接近并小于nD态的能级．这一现象不同于通常的碱金属原子的Stark结构，论文对该现象及其他Stark能级结构特征进行了详细分析，为相关研究工作提供了重要参考价值．

英文摘要：

The Stark effect in Rydberg atoms has potential applications in the areas of dipole-dipole interaction, quantum information, quantum control, and so on. Many relevant theoretical calculations and experimental studies about the Stark effect of alkali metal and alkali earth metals have been reported, but the other atom＇s Stark effect is studied still relatively less. Our goal in this paper is to research the third main group atom＇s Stark effect in a large electric field. First, according to the level data of gallium atom in zero-field, we obtain the quantum defects from the modified Ritz formula in each state by using a nonlinear least-squares-fitting algorithm. The quantum defects as a function of the principal quantum number are analyzed in detail. Influences of both the core polarization and the penetrating valence electron on the quantum defect are discussed according to the fitting results. Then we use the Numerov algorithm to calculate the radial wave functions of atomic gallium. Finally, the Stark structures of Rydberg states around n = 7 and n = 18 are numerically calculated by matrix diagonalization. Results show that at the levels above n ---- 7 manifold states, （n ~ 1）P is higher than nD state, and it is in contrast to the levels below the n = 7 manifold states. This phenomenon is different from the usual Stark structure of alkali metal atoms, the leveFs order of which does not change with the principal quantum number. The Stark levels with the identical m anti-cross each other, and those with different m cross. Our results give an important reference for related researches, and are of great significance for insight into the atomic structure and the interaction between the atomic core and the highly excited electrons.