Electronic structure and ultrafast dynamics of FeAs-based superconductors by angle- and timeresolved photoemission spectroscopy

通过角和时间分辨光电子能谱研究 FeAs 基超导体的电子结构和超快动力学

• 批准号: 168637527
• 负责人: Professor Dr. Uwe Bovensiepen
• 金额: --
• 依托单位: Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden (IFW) e.V.
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/168637527?language=en
• 关键词: Electronic; structure; ultrafast; dynamics; FeAs

This project is focused on the determination of the doping-dependent electronic structure of iron-pnictide and iron-chalcogenide-based high-Tc superconductors and their parent compounds. The band structure of these materials and in particular the Fermi surface of these multiband systems is a major ingredient for the understanding of superconductivity, since it is generally believed that the antiferromagnetic order of the parent compounds and superconductivity in the doped compounds is related to a nesting between hole-pockets in the centre and electron pockets at the boundary of the Brillouin zone. For these studies we use both high-resolution angle-resolved photoemission spectroscopy (ARPES) with variable photon energies (synchrotron radiation) and the complementary technique of femtosecond time-resolved ARPES. This unique combination provides direct access to the electronic structure and quasiparticle scattering dynamics below and above the Fermi level for holes and electrons, respectively. We intend to analyze the symmetry of the superconducting gap by measuring the anisotropy of the gap not only parallel but also perpendicular to the layers. In addition important complementary information on the coupling of the charge carriers to bosonic excitations (phonons, spin fluctuations) and electron-electron scattering can be derived in the frequency and time domain. This is essential for the understanding of the superconducting state. For these investigations a close collaboration with other experimental and theoretical groups within the priority program is anticipated. Our work is based on the availability of single crystals grown in other groups.

本计画的重点是铁磷属化物和铁硫属化物基高温超导体及其母体化合物的掺杂相关电子结构的测定。这些材料的能带结构，特别是这些多带系统的费米面，是理解超导性的主要成分，因为人们普遍认为，母体化合物的反铁磁顺序和掺杂化合物的超导性与布里渊区中心的空穴袋和边界处的电子袋之间的嵌套有关。对于这些研究，我们使用高分辨率角分辨光电子能谱（ARPES）与可变光子能量（同步辐射）和飞秒时间分辨ARPES的互补技术。这种独特的组合提供了直接访问的电子结构和准粒子散射动力学低于和高于费米能级的空穴和电子，分别。我们打算通过测量差距的各向异性来分析超导带隙的对称性。此外，重要的补充信息的耦合的载流子玻色子激发（声子，自旋波动）和电子-电子散射可以在频域和时域中导出。这对于理解超导态是必不可少的。对于这些研究，预计将与优先计划内的其他实验和理论小组密切合作。我们的工作是基于在其他群体中生长的单晶的可用性。