Epitaxial growth and characterization of Bi1-xSbx spin Hall thin films on GaAs(111)A substrates
Epitaxial growth and characterization of Bi1-xSbx spin Hall thin films on GaAs(111)A substrates
复制标题
DOI：
10.1063/1.4975492
复制
发表时间：
2017-02
影响因子：
4
通讯作者：
Yugo Ueda;N. H. D. Khang;Kenichiro Yao;P. Hai
中科院分区：
文献类型：
--
作者：
Yugo Ueda;N. H. D. Khang;Kenichiro Yao;P. Hai
采用分子束外延技术在GaAs(111)A衬底上生长了Bi1-xSbx薄膜，并对其进行了表征。通过优化生长条件，我们能够外延生长出Sb浓度为0%~100%，外延取向为Bi1-xSbx(001)//GaAs(111)的Bi1-xSbx薄膜。Bi1-xSbx的电导率超过105Ω−1m−1，接近足够厚薄膜的体积值，至少比其他铋基拓扑绝缘体高一个数量级。从Bi1-xSbx的电导率对温度的依赖关系，我们证实了Bi1-xSbx在拓扑绝缘区内外存在金属表面态。我们的结果证明了Bi1-xSbx作为自旋霍尔材料的潜力，该材料具有高电导率和可能的大自旋霍尔角，可用于自旋电子应用。
We grew and characterized Bi1-xSbx thin films on GaAs(111)A substrates by molecular beam epitaxy. By optimizing the growth condition, we were able to grow Bi1-xSbx thin films epitaxially with the Sb concentration ranging from 0% to 100% and the epitaxial orientation of Bi1-xSbx(001)//GaAs(111). The conductivity of Bi1-xSbx exceeds 105 Ω−1 m−1 and approaches those of bulk values for thick enough thin films, which are higher than those of other Bi-based topological insulators by at least an order of magnitude. From the temperature dependence of their electrical conductivity, we confirmed the existence of metallic surface states of Bi1-xSbx inside and outside of the topological insulating region. Our results demonstrate the potential of Bi1-xSbx as a spin Hall material with high conductivity and possibly large spin Hall angle for spintronic applications.