Dirac cone and pseudogapped density of states in the topological half-Heusler compound YPtBi
Dirac cone and pseudogapped density of states in the topological half-Heusler compound YPtBi
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DOI：
10.1103/physrevb.94.161108
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发表时间：
2016-10-06
影响因子：
3.7
通讯作者：
Jourdan, M.
中科院分区：
文献类型：
--
作者：
Kronenberg, A.;Braun, J.;Jourdan, M.
拓扑绝缘体(TIS)是一种令人兴奋的材料，它表现出前所未有的性质，如螺旋自旋-动量锁定，这导致了大的磁开关扭矩和高效的自旋电流检测。这里我们以化合物YPtBi为例，预测了典型的拓扑绝缘体的能带反转。我们用传统的共溅射方法从基本靶上制备了这种材料的薄膜。用原位飞行时间动量显微镜观察到Dirac锥形表面态，其Dirac点接近或等于费米能量以下300 meV，这与电子结构-光电子能理论计算的结果一致。在E-F处只观察到由于其他状态引起的很少的额外谱重，这证实了拓扑保护的表面态的识别，并且与自旋电子学的应用高度相关。
Topological insulators (TIs) are exciting materials, which exhibit unprecedented properties, such as helical spin-momentum locking, which leads to large torques for magnetic switching and highly efficient spin current detection. Here we explore the compound YPtBi, an example from the class of half-Heusler materials, for which the typical band inversion of topological insulators was predicted. We prepared this material as thin films by conventional cosputtering from elementary targets. By in situ time-of-flight momentum microscopy, a Dirac conelike surface state with a Dirac point similar or equal to 300 meV below the Fermi energy was observed, in agreement with electronic structure-photoemission calculations. Only little additional spectral weight due to other states was observed at E-F, which corroborates the identification of the topologically protected surface state and is highly relevant for spintronics applications.