Microscale and Nanoscale Physics of Topological Metals

拓扑金属的微观和纳米物理

• 批准号: 506208038
• 负责人: Dr. Maxim Breitkreiz
• 金额: --
• 依托单位: Dahlem Center für komplexe Quantensysteme (DCCQS)
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/506208038?language=en
• 关键词: Microscale; Nanoscale; Physics; Topological; Metals

Topological metals are characterized by the presence of topologically protected band-touching points that resemble the dispersion of elementary Weyl Fermions or various generalizations of it. Since the first experimental discovery in 2015, topological metals constitute a broad field of contemporary condensed-matter research. Much less explored systems are those which emerge when the size of the topological metal is reduced to the micro- or nanoscale, such as in thin films. The main peculiarity of these materials is not the presence of Weyl Fermions, which topological protection is confinement-broken, but the novel property of Fermi-level states being simultaneously connected in momentum space and disconnected in real space. Preliminary research indicates that this peculiarity has far reaching consequences in a variety of effects. In particular, we encounter the possibility for a novel topological classification of these metals, an unconventional diffusive behaviour, a rich, controllable response to incident light, and peculiar response to proximitized superconductivity. This Emmy-Noether project will act in form of similarly diversified subprojects, connected by the goal to provide a broad theoretical understanding of these systems and push their experimental realization. Specifically, we will explore possibilities to design the Fermi surface of these metals in topologically different shapes, enhance various response coefficients, including conductivity and the conversion of light into electric current, and enable density-wave order. The peculiarity of these systems brings computational challenges, arising from the symmetry-breaking spatial confinement and the interconnection of spatial and momentum degrees of freedom. We will use various known analytical and numerical techniques, which we will combine and extend in novel ways to be applicable for these systems.

拓扑金属的特点是存在拓扑保护的带接触点，类似于基本Weyl费米子或其各种推广的分散。自2015年第一个实验发现以来，拓扑金属构成了当代凝聚态研究的广泛领域。较少探索的系统是当拓扑金属的尺寸减小到微米或纳米级时出现的那些系统，例如在薄膜中。这些材料的主要特点不是拓扑保护被打破的Weyl Fermion的存在，而是Fermi能级态在动量空间中同时连通而在真实的空间中同时不连通的新特性。 初步研究表明，这种特殊性在各种影响中具有深远的影响。特别是，我们遇到了一种新的拓扑分类这些金属的可能性，一个非常规的扩散行为，丰富的，可控的响应入射光，和特殊的响应proximitized超导。这个Emmy-Noether项目将以类似的多样化子项目的形式进行，通过目标连接，以提供对这些系统的广泛理论理解并推动其实验实现。具体来说，我们将探索设计这些金属的费米表面在拓扑上不同的形状，提高各种响应系数，包括电导率和光到电流的转换，并使密度波秩序的可能性。这些系统的特殊性带来了计算上的挑战，这是由于空间限制的破坏以及空间和动量自由度的相互连接。我们将使用各种已知的分析和数值技术，我们将联合收割机，并扩展到适用于这些系统的新方法。