arXivDaily arXiv每日学术速递 周一至周五更新
arXiv physics/0611122physics.atom-phphysics.optics
收藏

laser修饰原子的X射线吸收理论

Theory of x-ray absorption by laser-dressed atoms

Christian Buth, Robin Santra

摘要:

本文用从头算方法研究了中等强度激光(800 nm,10^13 W/cm ^2)场中原子的X射线光吸收截面。该激光器修饰了芯激发原子态,这引入了截面对两个线偏振辐射源的偏振矢量之间的角度的依赖性。我们使用Hartree-Fock-Slater近似来描述原子的多粒子问题,结合非相对论量子电动力学方法来处理光子-电子相互作用。连续波函数的喷射电子处理与复杂的吸收势,来自光滑的外部复杂的缩放。本文讨论了用复对称矩阵表示哈密顿量的直接对角化方法解决双色(X射线加激光)问题。利用X射线与原子之间的弱相互作用强度,提出了与时间无关和与时间相关的非厄米特微扰理论的替代治疗。我们应用该理论研究了氪原子在K边附近的光吸收截面。在光学激光的存在下,发现截面发生了显着的变化。

英文摘要:

An ab initio theory is devised for the x-ray photoabsorption cross section of atoms in the field of a moderately intense optical laser (800nm, 10^13 W/cm^2). The laser dresses the core-excited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the Hartree-Fock-Slater approximation to describe the atomic many-particle problem in conjunction with a nonrelativistic quantum-electrodynamic approach to treat the photon-electron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smooth exterior complex scaling. The solution to the two-color (x-ray plus laser) problem is discussed in terms of a direct diagonalization of the complex symmetric matrix representation of the Hamiltonian. Alternative treatments with time-independent and time-dependent non-Hermitian perturbation theories are presented that exploit the weak interaction strength between x rays and atoms. We apply the theory to study the photoabsorption cross section of krypton atoms near the K edge. A pronounced modification of the cross section is found in the presence of the optical laser.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑