Calculation of energy levels and transition amplitudes for barium and radium

Calculations of energy levels and lifetimes of low-lying states of barium and radium

We use the configuration interaction method and many-body perturbation theory to perform accurate calculations of energy levels, transition amplitudes, and lifetimes of low-lying states of barium and radium. Calculations for radium are needed for the planning of measurements of parity and time invariance violating effects which are strongly enhanced in this atom. Calculations for barium are used to control the accuracy of the calculations.

Spectra of barium, radium, and element 120; application of the combined correlation potential, singles-doubles, and configuration interaction ab initio method

We apply a version of the recently developed approach combining the correlation potential, linearized singles-doubles coupled-cluster, and the configuration interaction methods to the spectra of the heavy alkaline earths barium, radium, and element 120. Quantum electrodynamics radiative corrections are included. We have found unprecedented agreement between ab initio theory and experiment for the spectra of barium and radium, and we make accurate predictions for missing and unreliable data for all three atoms.

Radium ion: A possible candidate for measuring atomic parity violation

Single trapped and laser cooled Radium ion as a possible candidate for measuring the parity violation induced frequency shift has been discussed here. Even though the technique to be used is similar to that proposed by Fortson [1], Radium has its own advantages and disadvantages. The most attractive part of Radium ion as compared to that of Barium ion is its mass which comes along with added complexity of instability as well as other issues which are discussed here

Coherent Dark Resonances in Atomic Barium

The observation of dark-resonances in the two-electron atom barium and their influence on optical cooling is reported. In heavy alkali earth atoms, i.e. barium or radium, optical cooling can be achieved using n^1S_0-n^1P_1 transitions and optical repumping from the low lying n^1D_2 and n^3D_{1,2} states to which the atoms decay with a high branching ratio. The cooling and repumping transition have a common upper state. This leads to dark resonances and hence make optical cooling less inefficient. The experimental observations can be accurately modelled by the optical Bloch equations. Compariso…

钡 II 和镭 II 离子的理论表征

Theoretical characterisation of the barium II and radium II ions

本文采用含 Breit 和 QED 修正的全阶关联势方法，高精度计算 Ra+ 与 Ba+ 的跃迁矩阵元、寿命、极化率等，并提取 E2 矩阵元及核磁化分布参数。

Calculation of the spectrum of the superheavy element Z=120

High-precision calculations of the energy levels of the superheavy element Z=120 are presented. The relativistic Hartree-Fock and configuration interaction techniques are employed. The correlations between core and valence electrons are treated by means of the correlation potential method and many-body perturbation theory. Similar calculations for barium and radium are used to gauge the accuracy of the calculations and to improve the ab initio results.