论文标题
墨西哥帽子拓扑半导体的巨型光子响应，用于中红外的THZ应用
Giant Photonic Response of Mexican-hat Topological Semiconductors for Mid-infrared to THz Applications
论文作者
论文摘要
到Terahertz（THz）频率的中红外（miR），远红外（FIR）是用于应用的电磁频谱中最不发达的部分。传统的半导体技术（如激光二极管和光电探测器）在可见光范围内取得了成功，但是当扩展到mir/fir/thz范围时，仍然面临着巨大的挑战。在本文中，我们证明了拓扑绝缘子（TIS），尤其是那些具有墨西哥帽子带结构（MHB）的绝缘体，提供了克服这些挑战的途径。 MHBS TI的光学响应可以比光学转变边缘处的正常半导体大的数量级。我们探索拓扑材料的数据库，并发现许多MHB的带盖在$ 0.05 \ sim 0.5〜 \ rm eV $之间，并在$ 10^4 \ sim 10^4 \ sim 10^5〜〜 \ rm cm cm cm cm^{ - 1} $上具有巨大的收益（吸收系数）。这些发现可能会显着提高潜在的miR/fir/THz应用，例如光子源，检测器，超快电流设备和量子信息技术。
The mid-infrared (MIR), far-infrared (FIR) to terahertz (THz) frequencies are the least developed parts of the electromagnetic spectrum for applications. Traditional semiconductor technologies like laser diodes and photodetectors are successful in the visible light range, but are still confronted with great challenges when extended into the MIR/FIR/THz range. In this paper, we demonstrate that topological insulators (TIs), especially those with Mexican-hat band structure (MHBS), provide a route to overcome these challenges. The optical responses of MHBS TIs can be one to two orders of magnitude larger than that of normal semiconductors at the optical-transition edge. We explore the databases of topological materials and discover a number of MHBS TIs whose bandgaps lie between $0.05\sim 0.5~\rm eV$ and possess giant gains (absorption coefficients) on the order of $10^4 \sim 10^5~\rm cm^{-1}$ at the transition edge. These findings may significantly boost potential MIR/FIR/THz applications such as photon sources, detectors, ultrafast electro-optical devices, and quantum information technologies.
