Theory of resonant x-ray scattering and the establishment of the ab initio calculation method of the associated excited states

X射线共振散射理论及相关激发态从头计算方法的建立

• 批准号: 14540323
• 负责人: IGARASHI Jun-ichi
• 金额: $ 0.9万
• 依托单位: Japan Atomic Energy Research Institute
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540323/
• 关键词: resonant x-ray scattering (RXS); resonant inelastic scattering (RIXS); K absorption edge; orbital order; magnetic order; 4p electronic state; spin-orbit interaction; 共鳴X線散乱; 磁気円二色性; 格子歪

We have studied the mechanism of the resonant x-ray scattering (RXS) from the microscopic viewpoint, and have obtained the following results :Elastic scattering(1)We have analyzed the RXS spectra at the magnetic superlattice spots around the Cu K edge in the antiferromagnet KCuF_3 and around the Ni K edge in NiO. Taking account of the spin-orbit interaction, we have carried out ab initio calculations within the local density approximation. We have explained various experimental facts, having clarified the mechanism of the orbital polarization on the zip band.(2)We have analyzed the RXS spectra at the magnetic superlattice spots around the Ga K edge in the antiferromagnet UGa_3 by carrying out the ab initio calculation with taking account of the spin-orbit interaction. We have clarified tha mechanism that the large orbital polarization in the 4p band of UGa3 arises from the large orbital moment of U atoms through the mixing between the Ga 4p states and the U 5f states. The experimental … More large spectral intensitieshave been explained naturally by the analysis.(3)We have analyzed the RXS spectra at the quadrupole ordering superlattice spots in CeB_6 on the basis of an atomic model including Ce4f-Ce4f interatomic interaction. The interference between the resonant scattering and the Thomson scattering found in the experiment have been well reproduced without assuming the lattice distortion.Inelastic scattering(1)We have analyzed the resonant inelastic scattering (RIXS) spectra around the Ge K edge on the basis of the ab initio calculation. The experimental spectra have been well reproduced, and the relation between the spectra and the band mapping has been clarified.(2)We have analyzed the RIXS spectra around the Cu K edge in La_2CuO_4 on the basis of the d-p model. Using the Hartree-Fock approximation together with the random phase approximation, we have calculated the spectra in good agreement with the experiment. We have clarified the mechanism for the move of the the spectral peak with varying final-state momenta. Less

我们从微观的角度研究了谐振X射线散射（RX）的机制，并获得了以下结果：弹性散射（1）我们已经在抗Fiferromagnet KCUF_3和Ni k Edge in nio中分析了磁性超晶格围绕磁性超晶格斑点的RxS光谱。考虑到自旋轨道相互作用，我们在局部密度近似中进行了从头算的计算。我们已经解释了各种实验事实，并阐明了邮政带上的轨道极化机制。（2）我们通过考虑抗iga_3的Ga k边缘周围的磁性超晶格斑点分析了RXS光谱，通过考虑抗iga_3的抗fiferromagnet UGA_3中的AB Initio计算，并考虑了自旋宏观的相互作用。我们已经阐明了Tha机制，即UGA3 4p带中的大轨道极化是由U原子的大轨道矩通过GA 4P状态和U 5F状态之间的混合而产生的。实验性……更大的光谱强度已经通过分析自然解释了。（3）我们已经根据包括CE4F-CE4F的原子模型，分析了CEB_6中ceb_6中超级晶格点的RXS光谱。在没有假设晶格失真的情况下，已经很好地再现了谐振散射与汤森散射之间的相互作用。矿物散射（1）我们已经在AB Initio计算的基础上分析了GE K边缘周围GE K边缘的谐振非弹性散射（RIX）光谱。实验光谱已经很好地再现了，并且阐明了光谱与频带映射之间的关系。（2）我们根据D-P模型分析了LA_2CUO_4中Cu K边缘周围的RIXS光谱。使用Hartree-fock近似以及随机相位近似，我们已经计算出与实验非常吻合的光谱。我们已经阐明了光谱峰的移动机制，并以不同的最终元动量变化。较少的

项目成果

M.Usuda, M.Takahashi, J.Igarashi: "An Ab-Initio Calculation of Magnetic Resonant X-Ray Scattering Spectra in NiO"Phys.Rev.B. 69. 014408(1)-014408(7) (2004)

M.Usuda、M.Takahashi、J.Igarashi：“NiO 中磁共振 X 射线散射光谱的从头算”Phys.Rev.B。

M.Usuda: "An Ab-Initio Calculation of Magnetic Resonant X-Ray Scattering Spectra in NiO"Physical Review B. 69. 014408(1)-014408(7) (2004)

M.Usuda：“NiO 中磁共振 X 射线散射光谱的从头计算”物理评论 B. 69. 014408(1)-014408(7) (2004)

T.Nagao, J.Igarashi: "Interference between Thomson Scattering and Resonant Scattering in X-Ray Diffraction from CeB_6"J.Phys.Soc.Jpn.. 72-9. 2381-2384 (2003)

T.Nagao、J.Igarashi：“来自 CeB_6 的 X 射线衍射中汤姆逊散射和共振散射之间的干涉”J.Phys.Soc.Jpn.. 72-9。

T.Nagao: "Interference between Thomson Scattering and Resonant Scattering in X-Ray Diffraction from CeB_6"J.Phys.Soc.Jpn.. 72. 2381-2384 (2003)

T.Nagao：“来自 CeB_6 的 X 射线衍射中汤姆逊散射和共振散射之间的干涉”J.Phys.Soc.Jpn.. 72. 2381-2384 (2003)

Y.Nishikawa: "Resonant Inelastic X-Ray Scattering at the K Edge of Ge"J.Phys.Soc.Jpn.. (掲載予定). (2004)

Y.Nishikawa：“Ge K 边缘处的共振非弹性 X 射线散射”J.Phys.Soc.Jpn..（待出版）。