论文标题
检查二维圆锥模型的有效性来描述三维ZRTE5
Examining the validity of the two-dimensional conical model to describe the three-dimensional ZrTe5
论文作者
论文摘要
在新型拓扑材料研究中，了解三维层状化合物ZRTE5中低能激发态仍然是一个具有挑战性的问题。最近，提出了一个二维圆锥模型来解释3D ZRTE5中的实验光谱法，Martino等。 [物理。莱特牧师。 122，217402（2019）]。在本文中，在本文中，我们在没有外部磁场的情况下对该模型的光电性进行了系统的理论研究，以进一步证明该模型的有效性并恢复新物理学的有效性。我们发现，由于这种两极分化的模型，由于具有不同方向的光电性特征在不同的方向上存在完全不同的特征。具体而言，对于带的光学电导率，我们发现对光学频率的渐近依赖性为RE（σ_x）\simΩ^{1/2}和re（σ_z）\simΩ^{3/2}，它们在间隙绝缘剂相和Weyl semimetal相中都是通用的。相反，对于磁光电导率，re（σ^b_ {x/z}）在裂开的绝缘体相和Weyl semimetal阶段中显示出不同的签名，这可以帮助区分这两个阶段。我们的结果将在未来的实验中得到验证，可以提供更多有关ZRTE5拓扑性质的了解。
Understanding the low-energy excitation state in three-dimensional layered compound ZrTe5 remains a challenging problem in the study of novel topological materials. Recently, a two-dimensional conical model was proposed to explain the experimental optical spectroscopy in the 3D ZrTe5, Martino et al. [Phys. Rev. Lett. 122, 217402 (2019)]. Motivated by this work, in this paper, we perform a systematic theoretical study on the optical conductivity of this model in both cases without and with an external magnetic field to further demonstrate the validity of this model and to recover new physics.We find that there exist completely different characteristics for optical conductivity along different directions, due to anisotropic low-energy excitations in this two-dimensional conical model. Specifically, for the interband optical conductivity, we find asymptotic dependence on the optical frequency as Re(σ_x)\simω^{1/2} and Re(σ_z)\simω^{3/2}, which are universal both in the gapped insulator phase and Weyl semimetal phase. For the magneto-optical conductivity, on the contrary, Re(σ^B_{x/z}) shows distinct signatures in the gapped insulator phase and Weyl semimetal phase, which can help distinguish the two phases. Our results, to be verified in future experiments, could provide more insights into the understanding of the topological nature of ZrTe5.
