Ideal near-Dirac triple-point semimetal in III-V semiconductor alloys
Ideal near-Dirac triple-point semimetal in III-V semiconductor alloys
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DOI：
10.1103/physrevb.101.125202
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发表时间：
2020-03-18
影响因子：
3.7
通讯作者：
Rappe, Andrew M.
中科院分区：
文献类型：
--
作者：
Fang, Zhenyao;Gao, Heng;Rappe, Andrew M.
尽管人们对拓扑材料越来越感兴趣，但实验合成并将其与其他材料集成的困难一直是限制获得其独特性能的主要障碍之一。最近在合成晶体材料亚稳相方面的进展有助于克服这一障碍，并为实验研究和操纵能带拓扑提供了新的平台。由于III-V族半导体具有广泛的功能材料应用（包括光电器件，发光二极管和高效太阳能电池），并且由于Bi掺杂的III-V族材料可以通过离子种植园和离子截止方法合成，因此我们重新审视了亚稳态III-V族半导体中的铋取代效应。通过第一性原理计算方法，我们发现在纤锌矿结构的III-V族材料中，Bi替代可以导致能带反转现象，并诱导出非平凡的拓扑性质。GaBi和InBi是Dirac-Weyl半金属，其特征是Dirac点和Weyl点共存; GaAs0.5Bi0.5，GaSb0.5B0.5，InSb0.5Bi0.5是三相点半金属，其特征是费米能级上有两组“近Dirac”三相点.这些实验上可访问的铋基拓扑半金属可以集成到大家庭的功能III-V族材料的异质结构和未来的光电应用的实验研究。
Despite the growing interest in topological materials, the difficulty of experimentally synthesizing and integrating them with other materials has been one of the main barriers restricting access to their unique properties. Recent advances in synthesizing metastable phases of crystalline materials can help to overcome this barrier and offer new platforms to experimentally study and manipulate band topology. Because III-V semiconductors have a wide range of functional material applications (including optoelectronic devices, light-emitting diodes, and highly efficient solar cells) and because Bi-doped III-V materials can be synthesized by ion plantation and ion-cutoff methods, we revisit the effect of bismuth substitution in metastable III-V semiconductors. Through first-principles calculation methods, we show that in wurtzite structure III-V materials, Bi substitution can lead to band inversion phenomena and induce nontrivial topological properties. Specifically, we identify that GaBi and InBi are Dirac-Weyl semimetals, characterized by the coexistence of Dirac points and Weyl points, and GaAs0.5Bi0.5, GaSb0.5 B0.5, InSb0.5Bi0.5 are triple-point semimetals, characterized by two sets of "near-Dirac" triple points on the Fermi level. These experimentally accessible bismuth-based topological semimetals can be integrated into the large family of functional III-V materials for experimental studies of heterostructures and future optoelectronic applications.