Ultra-thin topological insulator spin-current transistor

超薄拓扑绝缘体自旋电流晶体管

• 批准号: 2881674
• 金额: --
• 依托单位: University of Leeds
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2881674
• 关键词: Ultra; thin; topological; insulator; spin

Topological insulators are an existing class of band-gap insulators, whilst they do conduct through their edge (or the surface in the case of 3 dimensional materials). These gapless metallic surface states are naturally generated with helically polarized spin texture due to strong spin-orbit coupling with a peculiar energy band structure of materials. Moreover, the states are protected by time-reversal symmetry simply due to prohibition of back scattering and realize almost dissipation-less pure spin currents (no net charge current) at the edge (surface) of materials. Spin-current devices based on the topological insulators save energy because it requires small current that flow at the edge (the surface) not in the bulk to access their surface properties. In this project, we will fabricate a spin-current field effect transistor with an ultra-thin topological insulator Bi2-xSbxTe3 and GeTe (a Weyl semimetal candidate) films grown by molecular beam epitaxy in ultrahigh vacuum, a part of a new multi-deposition system in Leeds. Existence of gapless states in topological insulators (topological Weyl semimetals) are one of peculiar characteristics but we will open a gap in the surface state by employing ultra-thin films where the top and bottom surface states get unstable due to an interference between two. The gapped surface state with a gating technique will provide us a capability of fabricating a spin-current filed effect transistor that can switch on/off the spin-polarized current. We will also keep our eye on other topological insulator materials suitable for this device project. This is a project in an exciting and very active research area which allows us to closely interact and collaborate with other research teams in the University of Leeds including a theoretical group. We are looking for a motivated student with a background in physics, physical chemistry, or material science

拓扑绝缘子是现有的带隙绝缘子，而它们确实通过边缘进行（或3尺寸材料的表面）。这些无间隙的金属表面状态是自然而然地用螺旋极化的自旋纹理产生的，这是由于强旋轨耦合与材料的特殊能带结构。此外，仅由于禁止背部散射而受到时间反向对称性的保护，并在材料的边缘（表面）处实现了几乎无耗散的纯旋转电流（无净电荷电流）。基于拓扑绝缘体的自旋电流设备可节省能量，因为它需要在边缘流动（表面）的小电流，而不是散装以获取其表面性能。 在这个项目中，我们将使用超薄拓扑拓扑效应晶体管使用超薄拓扑绝缘子BI2-XSBXTE3和Gete（Weyl Semimetal候选）膜在Ultrahigh真空中通过分子束外观的生长而生长，这是Leeds中新的多重沉积系统的一部分。拓扑绝缘子（拓扑Weyl semimetals）中无间隙状态的存在是特征的特征之一，但是我们将通过使用超薄膜在表面状态下张开缝隙，因为两个膜由于两个之间的干扰，因此顶部和底部表面状态变得不稳定。带有门控技术的间隙表面状态将为我们提供制造自旋流动效应晶体管的能力，该效应晶体管可以打开/关闭自旋偏振电流。我们还将关注其他适合此设备项目的拓扑绝缘材料。 这是一个令人兴奋且非常活跃的研究领域的项目，它使我们能够与利兹大学的其他研究团队进行紧密互动和合作，包括理论小组。我们正在寻找具有物理，物理化学或材料科学背景背景的有动力的学生