Atomic-scale magnetic architectures with unconventional magnonic states

具有非常规磁能态的原子尺度磁性结构

• 批准号: 524533417
• 负责人: Privatdozent Dr. Khalil Zakeri Lori
• 金额: --
• 依托单位: Physikalisches Institut (PHI)
• 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/524533417?language=en
• 关键词: Atomic; scale; magnetic; architectures; unconventional

The concept of electronic band structure is one of the most important concepts in condensed-matter physics. It is an essential concept to understand both the physical and chemical properties of materials. In a solid, due to the broken translation symmetry at the surface (interface) new electronic states may appear, i.e., the surface (interface) states. In the so-called topological solids and under some circumstances, these states are topologically protected. The concept of topologically protected states is not limited to the fermionic quasiparticles. Similarly, the collective bosonic excitations e.g., phonons, plasmon, and magnons can also exhibit unconventional surface (interface) states, which are topologically protected. Owing to their unique properties, topologically protected states may be utilized for practical applications in spintronic or magnonic devices. In this project, by investigating model systems of atomically architectured epitaxial layers of ferromagnetic metals, we aim to introduce the concept of magnonic surface (interface) states and their possible topological protection in layered structures. For that, we plan to investigate layered ferromagnets designed in hcp(0001) stacking. We would like to, first, understand the physics of magnonic surface and interface states in these structures. We will probe the magnonic band structure in atomically designed layered systems with different sequences and number of atomic layers by means of spin-polarized high-resolution electron energy-loss spectroscopy. We will then carefully investigate the band formation in such structures. We shall identify the origin of the magnonic bands with respect to their real space localization and topology and provide new insights into the origin of each band and its topological nature.

电子能带结构是凝聚态物理中最重要的概念之一。它是了解材料物理和化学性质的一个重要概念。在固体中，由于在表面（界面）处的破缺平移对称性，可能出现新的电子状态，即，表面（界面）状态。在所谓的拓扑固体中，在某些情况下，这些状态是拓扑保护的。拓扑保护态的概念并不局限于费米子准粒子。类似地，集体玻色子激发，声子、等离子体激元和磁振子也可以表现出非常规的表面（界面）状态，其在拓扑上受到保护。由于它们独特的性质，拓扑保护态可以用于自旋电子或磁振子器件的实际应用。在这个项目中，通过研究铁磁金属原子结构外延层的模型系统，我们的目标是引入磁振子表面（界面）态的概念和它们在层状结构中可能的拓扑保护。为此，我们计划研究hcp（0001）堆叠设计的层状铁磁体。首先，我们想了解这些结构中磁振子表面和界面态的物理学。我们将通过自旋极化高分辨电子能量损失谱来探测原子设计的具有不同原子层顺序和数量的层状系统中的磁振子能带结构。然后，我们将仔细研究这种结构中的能带形成。我们将确定起源的磁振子带相对于他们的真实的空间定位和拓扑结构，并提供新的见解的起源，每个带及其拓扑性质。