论文标题
区分Zrte $ _5 $中的间隙和Weyl半学场景：有效的两波段模型的见解
Distinguishing the gapped and Weyl semimetal scenario in ZrTe$_5$: insights from an effective two-band model
论文作者
论文摘要
在这里，我们研究了E. Martino等人先前提出的低能两波段模型的静态和动态传输性能。 [PRL 122，217402（2019），ARXIV：1905.00280]，具有各向异性的平面内线性动量依赖性和抛物线外的平面外分散体。该模型的扩展为包括负带隙，这导致了Weyl sagimetal（WSM）状态的出现，而不是在带隙为正时的间隙半度（GSM）状态。我们计算和比较GSM和WSM案例的零和有限频率传输性能。针对GSM和WSM案例计算的$ DC $属性是drude频谱的重量，移动性和电阻率。我们确定它们对费米能量和晶体方向的依赖性。平面内和偏僻的光电电导率是在两个半学的消失的带间弛豫率的限制下计算的。主要的共同特征是$ω^{1/2} $ in-plane和$ω^{3/2} $ of-prane频率依赖于光学电导率。根据与实验的比较，我们寻求与电荷运输相关的特定特征，该功能可能明确指向一个基态。 WSM和GSM之间的差异原则上只有在极低的载体浓度和低温下才有可能。
Here we study the static and dynamic transport properties of a low energy two-band model proposed previously in E. Martino et al. [PRL 122, 217402 (2019), arXiv:1905.00280], with an anisotropic in-plane linear momentum dependence, and a parabolic out-of-plane dispersion. The model is extended to include a negative band gap, which leads to the emergence of a Weyl semimetal (WSM) state, as opposed to the gapped semimetal (GSM) state when the band gap is positive. We calculate and compare the zero and finite frequency transport properties of the GSM and WSM cases. The $dc$ properties that are calculated for the GSM and WSM cases are Drude spectral weight, mobility and resistivity. We determine their dependence on the Fermi energy and crystal direction. The in- and out-of-plane optical conductivities are calculated in the limit of the vanishing interband relaxation rate for both semimetals. The main common features are an $ω^{1/2}$ in-plane and $ω^{3/2}$ out-of-plane frequency dependence of the optical conductivity. We seek particular features related to the charge transport that could unambiguously point to one ground state over the other, based on the comparison with the experiment. Differences between the WSM and GSM are in principle possible only at extremely low carrier concentrations, and at low temperatures.
