Abstract

In this paper, we study the feasibility of converting Heusler compounds X\(_2\)RuPb (X=Sc, Y, La) into three dimensional topological insulators. We perform first-principle calculations based on the full-potential linearized augmented plane wave (FP-LAPW) method within the density functional theory (DFT) using the general gradient approximation for the exchange and correlation potential (GGA-PBE). We investigate the topological insulator behavior of our compounds in the Hg\(_2\)CuTi-type Heusler structure in terms of the electronic band inversion mechanism tuned by the spin-orbit coupling and by applying a hydrostatic strain along with a uni-axial strain which inverts the band order between \(\varGamma _6\) and \(\varGamma _8\) bands: we realized a topological phase transition from a trivial semiconductor to nontrivial topological insulator. Then, we discuss the effects of these various strains on the topology band as well as on the real and imaginary parts of the dielectric function and related optical constants.

Graphic abstract

中文翻译：

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基于重元素的 Heusler 化合物的电子和拓扑性质 X $$_2$$ 2 RuPb (X=Sc,Y,La)：第一性原理方法

摘要

在本文中，我们研究了将 Heusler 化合物 X \(_2\) RuPb (X=Sc, Y, La) 转化为三维拓扑绝缘体的可行性。我们基于密度泛函理论 (DFT) 中的全电位线性化增强平面波 (FP-LAPW) 方法，使用交换和相关电位的一般梯度近似 (GGA-PBE) 进行第一性原理计算。我们研究了我们的化合物在 Hg \(_2\) CuTi 型 Heusler 结构中的拓扑绝缘体行为，其电子能带反转机制由自旋轨道耦合调节，并通过施加流体静力应变和单轴应变它反转了\(\varGamma _6\)和\(\varGamma _8\)之间的带序带：我们实现了从平凡半导体到非平凡拓扑绝缘体的拓扑相变。然后，我们讨论了这些不同应变对拓扑带以及介电函数的实部和虚部以及相关光学常数的影响。

图形摘要