Field-angular anisotropy of multipolar excitations

多极激励的场角各向异性

• 批准号: 446383824
• 负责人: Professor Dr. Dmytro Inosov, since 12/2020
• 金额: --
• 依托单位: Professur für Neutronenspektroskopie kondensierter Materie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/446383824?language=en
• 关键词: Field; angular; anisotropy; multipolar; excitations

One possible method for characterizing multipolar order in f-electron systems is to look at the magnetic excitation spectrum in an applied magnetic field, which bears the imprint of the multipolar interactions and the hidden order parameter in its dispersion relations. Using a specific candidate model, the dispersion for a given field is calculated and then compared to that measured with inelastic neutron scattering. Such an approach suffers from several shortcomings as well as some technical restrictions in the analysis of multipolar magnetic excitations and the possibility to obtain quantitative information about hidden-order symmetry and interactions between different multipoles. In this project I propose to establish a new paradigm to measure multipolar excitations in heavy fermion compound CeB6. In order to have a better comparison between the theory and experiment, it is worthwhile to keep the momentum transfer fixed and vary the field strength and field direction. For such measurements to be effective, we plan to build our own mechanical rotator compatible with the sample environment used in neutron scattering experiments. Such a rotator would facilitate the measurements of field-angular mode anisotropies and consequently improve our understanding of the physics of field-induced magnetic excitations. Measurements with the rotator will allow us to supplement the existing data on CeB6, obtained at the zone center with the magnetic field applied along several high-symmetry crystallographic directions, with the dependence of multipolar excitations on continuous field rotation and compare these results with the theoretically predicted polar anisotropy plots of multipolar excitations. As soon as additional crystals with different growth axes are grown, such measurements can be also obtained at different high-symmetry points of reciprocal space, which provides information that is impossible to obtain by any other experimental method. The results can be used to supply qualitatively new information about multipolar excitations to the theory collaborators and thereby enhance the methodology of determining microscopic interaction parameters between various multipoles in f-electron systems that is now being actively developed by various groups.

表征f-电子系统中多极序的一种可能方法是观察外加磁场中的磁激发谱，该谱带有多极相互作用的印记，并在其色散关系中隐藏了序参数。使用一个特定的候选模型，一个给定的字段的色散计算，然后与非弹性中子散射测量。这种方法存在一些缺点，以及在多极磁激励的分析和获得有关隐阶对称性和不同多极之间的相互作用的定量信息的可能性的一些技术限制。在这个项目中，我建议建立一个新的范式来测量重费米子化合物CeB 6的多极激发。为了更好地比较理论和实验，保持动量传递不变，改变场强和场方向是值得的。为了使这种测量有效，我们计划建立自己的机械旋转器，与中子散射实验中使用的样品环境兼容。这样的旋转器将有助于测量场角模各向异性，从而提高我们的理解的物理场致磁激发。与旋转器的测量将使我们能够补充现有的数据CeB 6，在区域中心获得的磁场施加沿沿着几个高对称性的结晶方向，与多极激发的依赖性连续场旋转和比较这些结果与理论预测的极性各向异性图的多极激发。一旦生长出具有不同生长轴的额外晶体，也可以在倒易空间的不同高对称点处获得这样的测量，这提供了通过任何其他实验方法不可能获得的信息。结果可以用来提供定性的多极激发的理论合作者的新信息，从而提高了确定微观之间的相互作用参数的f-电子系统，现在正在积极开发的各种团体。