Short-Time Dynamics and Electron-Lattice Interaction in Iron Based Superconductors

铁基超导体中的短时动力学和电子晶格相互作用

基本信息

批准号：
284271498
负责人：
Professor Dr. Ilya Eremin
金额：
--
依托单位：
Institut für Theoretische Physik III: Theoretische Festkörperphysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2015
资助国家：
德国
起止时间：
2014-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/284271498?language=en
关键词：
Short Time Dynamics Electron Lattice

项目摘要

Discovered in 2008, iron-based superconductors show superconductivity at temperatures as high as 55 K, and are currently being studied intensely worldwide. Their temperature-doping phase diagram is rich, having magnetic and nematic phases in addition to the superconducting one. It is now well-known that the magnetism and the superconductivity, arising from the electronic degrees of freedom, are sensitive to various deformations of the crystalline lattice. This electron-lattice coupling is an additional complexity, on top of that due to the electron-electron interaction, which makes a microscopic comprehension of these systems a formidable challenge. The aim of the proposal IRONIC is to perform very well-defined theoretical projects in order to quantify the different types of electron-lattice couplings in these materials, and to understand better the role of these couplings in establishing magnetic and superconducting order. A long-term benefit of research such as that proposed here is that, once well-understood, the electron-lattice coupling can, in principle, be tuned by material engineering to raise the superconducting transition temperature Tc.The scientific goals of the proposal are the following. (i) We note that, while there have been severalinteresting experimental breakthroughs in the use of pump-probe technique to study these systems, theoretically this area is currently not as well-developed. One aim will be to advance our theoretical understanding of such pump probe results, and to extract microscopic information such as those related to electron-lattice coupling, and those related to the exotic magnetic C4 phase. This will be achieved through a mix of symmetry-based Landau-Ginzburg approach as well as a more microscopic one where short timedynamics is captured using dynamical Bloch equations. (ii) The second goal is to study how unconventional electron-lattice coupling affects magnetic and nematic properties of these systems, as well as to theoretically understand how such couplings affect superconductivity.The originality of the proposal is its subject matter. There has been very little theoretical work in modeling pump-probe data in this field of research. Similarly, the effect of unusual electron-lattice coupling on the magnetic, nematic and superconducting phases of the FeSC remains largely unexplored theoretically, even though there are ample experimental evidences of such interactions.The project is divided into three tasks and six sub-tasks. Each of the two coordinators is in charge of three sub-tasks, and the tasks will be executed with the participation of two PhD students financed by the project, one each from the French and the German sides. The project requires several types of expertise, and the skills of the two partners are well complimented to meet the requirements. Furthermore, they have proven record of joint research. This ensures good synergy between them.

铁基超导体于 2008 年被发现，在高达 55 K 的温度下表现出超导性，目前全世界正在对其进行深入研究。它们的温度掺杂相图丰富，除了超导相之外，还具有磁性相和向列相。现在众所周知，由电子自由度产生的磁性和超导性对晶格的各种变形敏感。由于电子-电子相互作用，这种电子-晶格耦合是一种额外的复杂性，这使得对这些系统的微观理解成为一项艰巨的挑战。 IRONIC 提案的目的是执行非常明确的理论项目，以量化这些材料中不同类型的电子晶格耦合，并更好地理解这些耦合在建立磁和超导秩序中的作用。此处提出的研究的长期好处是，一旦被充分理解，电子晶格耦合原则上可以通过材料工程进行调整，以提高超导转变温度 Tc。该提案的科学目标是下列。（i）我们注意到，虽然在使用泵浦探针技术来研究这些系统方面已经取得了一些有趣的实验突破，但理论上该领域目前还没有那么发达。一个目标是推进我们对泵浦探测结果的理论理解，并提取微观信息，例如与电子晶格耦合相关的信息，以及与奇异磁性 C4 相相关的信息。这将通过结合基于对称性的朗道-金茨堡方法以及更微观的方法来实现，其中使用动态布洛赫方程捕获短时间动力学。（ii）第二个目标是研究非常规电子晶格耦合如何影响这些系统的磁性和向列性质，并从理论上理解这种耦合如何影响超导性。该提案的原创性是其主题。在这一研究领域中，对泵浦探测数据进行建模的理论工作非常少。同样，尽管有足够的实验证据证明这种相互作用，但不寻常的电子晶格耦合对 FeSC 的磁性、向列相和超导相的影响在理论上仍然很大程度上尚未得到探索。该项目分为三个任务和六个子任务。两名协调员各负责三项子任务，任务将由项目资助的两名博士生参与执行，法方和德方各一名。该项目需要多种类型的专业知识，两个合作伙伴的技能都足以满足要求。此外，他们还拥有联合研究的良好记录。这确保了它们之间良好的协同作用。