Transport and optical properties of the interacting electron gas in Weyl semimetals and two-dimensional materials

外尔半金属和二维材料中相互作用电子气的输运和光学性质

• 批准号: RGPIN-2019-06045
• 负责人: Côté, René
• 金额: $ 1.75万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=738676
• 关键词: Transport; optical; properties; interacting; electron

Title: Transport and optical properties of the interacting electron gas in Weyl semimetals and two-dimensional materials Summary: An electron gas can exist in different phases that determine to a large extent the physical properties of the host material. These phases are determined by internal parameters such as the band structure and dimensionality of the material as well as external parameters such as temperature, density and the presence of a magnetic or electric field. For example, when a two-dimensional electron gas is subjected to a strong perpendicular magnetic field, the kinetic energy of the electrons is quantized into degenerate Landau levels. The physical state of the gas is modified by changing the filling fraction of these levels. Since the 1980s, several phases have been identified such as the liquid state that exhibits the integer quantum Hall effect or more complex phases such as the fractional quantum Hall states or the electron crystal and stripes phases that can only be explained if the Coulomb interaction between electrons is taken into account. These complex states are collective states of the electron gas. In this proposal, we are interested in studying these collective states that are due to the combined presence of the Coulomb interaction and a magnetic field. We want to study their occurrence in quantum materials that have different band structures such as the two-dimensional electron gas in semiconductor quantum well and in graphene (a single layer of graphite) or the three-dimensional electron gas in Weyl semimetals, a material like graphene that has a topological band structure. We want to study the different phases of the electron gas that are possible when the magnetic field is varied and derive their single-particle excitations, collective modes as well as their electronic and optical properties. Our study will improve our understanding of the fundamental properties of quantum materials and help in finding properties that could be exploited to build new microelectronic devices.

职务名称：外尔半金属和二维材料中相互作用电子气的输运和光学性质摘要：电子气可以存在于不同的相中，这在很大程度上决定了主体材料的物理性质。这些相由内部参数（例如材料的能带结构和维度）以及外部参数（例如温度、密度和磁场或电场的存在）确定。例如，当二维电子气经受强垂直磁场时，电子的动能被量子化为简并的朗道能级。气体的物理状态通过改变这些水平的填充分数来修改。自20世纪80年代以来，已经确定了几个相，例如表现出整数量子霍尔效应的液态或更复杂的相，例如分数量子霍尔态或电子晶体和条纹相，如果考虑到电子之间的库仑相互作用，则只能解释。这些复杂的状态是电子气的集体状态。在这个提议中，我们感兴趣的是研究这些集体状态是由于库仑相互作用和磁场的组合存在。我们希望研究它们在具有不同能带结构的量子材料中的出现，例如半导体量子阱和石墨烯（单层石墨）中的二维电子气或Weyl半金属中的三维电子气，一种具有拓扑能带结构的石墨烯材料。我们想研究当磁场变化时可能出现的电子气的不同相，并推导出它们的单粒子激发，集体模式以及它们的电子和光学性质。我们的研究将提高我们对量子材料基本特性的理解，并有助于发现可用于构建新微电子器件的特性。