论文标题
拓扑结晶和普通绝缘子PB $ _ {1-x} $ sn $ _x $ se（111）表层探测光电谱探测器
Spin-polarization of topological crystalline and normal insulator Pb$_{1-x}$Sn$_x$Se (111) epilayers probed by photoelectron spectroscopy
论文作者
论文摘要
拓扑晶体绝缘子（TCI）表面上的螺旋旋转质地使这些材料可在旋转中使用。在这项工作中，（111）面向面向的Pb $ _ {1-x} $ sn $ _x $ se tci外生膜的表面状态的自旋偏振和电子结构通过角度检查 - 以及旋转分辨的光发射光谱光谱光谱法（SR-ARPES）。具有各种SN含量的高质量表层通过分子束外延（MBE）方法生长。观察到拓扑正常的绝缘体过渡表现为带隙开口。结果表明，间隙开口不仅可以通过更改表层的SN含量，还可以在其表面上沉积过渡金属（TM）来诱发。在后一种情况下，观察到的表面状态的间隙是由表面组成的变化而不是磁性引起的。我们还表明，螺旋自旋极化不仅适用于拓扑组成的样品，而且对于琐碎的样品（带有开放的带隙）存在。观察到的自旋极化的面积为30％，而平面外几乎不存在。我们认为，我们的工作将为在旋转荷利转化设备中基于铅键胆构的拓扑和正常绝缘体的表面状态铺平道路。
The helical spin texture on the surface of topological crystalline insulators (TCI) makes these materials attractive for application in spintronics. In this work, spin-polarization and electronic structure of surface states of (111)-oriented Pb$_{1-x}$Sn$_x$Se TCI epitaxial films are examined by angle -- as well as spin-resolved photoemission spectroscopy (SR-ARPES). High-quality epilayers with various Sn content are grown by the molecular beam epitaxy (MBE) method. Topological-normal insulator transition manifesting itself as band gap opening is observed. It is shown that the gap opening can be induced not only by changing the Sn content of the epilayer but also depositing a transition metal (TM) on its surface. In the latter case, the observed gaping of the surface states is caused by change in surface composition and not by magnetism. We also show that helical spin polarization is present not only for samples of topological composition but also for trivial ones (with an open band gap). The observed spin polarization reaches a value of 30 % for the in-plane spin component and is almost absent for the out-of-plane one. We believe that our work will pave the way for the application of surface states not only of topological but also normal insulators based on lead-tin chalcogenides in spin-charge conversion devices.
