论文标题
节点线半度Zrges和Zrgese的平面内和面外光学响应
In-plane and out-of-plane optical response of the nodal-line semimetals ZrGeS and ZrGeSe
论文作者
论文摘要
依赖极化的反射率测量是在单晶Zrgese和Zrges化合物上进行的，与原型Nodal-line半学ZRSIS密切相关。这些测量结果揭示了Zrgese和Zrges的强烈各向异性特征，在平面外方向{\ bf E} $ \ |的等离子频率降低。 C $与平面方向{\ bf e} $ \ |相比ab $。对于{\ bf e} $ \ | AB $光导率频谱由两个drude术语组成，后跟肩膀或平稳的行为和较高能量下的独特形状，而对于{\ bf e} $ \ | c $一个drude术语之后是峰状行为，并且轮廓的U形状较少发达。在外部压力下，ZRGESE的平面外光电频谱中出现了两次突出的激发，其频率位置和振荡器强度在$ \ sim $ 3〜GPA时显示出弱异常。总体而言，压力诱导的{\ bf e} $ \ |的轮廓变化的变化C $电导率频谱在$ \ sim $ 3〜GPA以上增强了。我们将我们的结果与最近报告的ZRSIS进行了比较。
Polarization-dependent reflectivity measurements were carried out over a broad frequency range on single-crystalline ZrGeSe and ZrGeS compounds, which are closely related to the prototype nodal-line semimetal ZrSiS. These measurements revealed the strongly anisotropic character of both ZrGeSe and ZrGeS, with a reduced plasma frequency for the out-of-plane direction {\bf E}$\| c$ as compared to the in-plane direction {\bf E}$\| ab$. For {\bf E}$\| ab$ the optical conductivity spectrum consists of two Drude terms followed by a shoulder or plateau-like behavior and a distinct U shape at higher energies, while for {\bf E}$\| c$ one Drude term is followed by a peak-like behavior and the U shape of the profile is less developed. Under external pressure, two prominent excitations appear in the out-of-plane optical conductivity spectrum of ZrGeSe, whose frequency position and oscillator strength show a weak anomaly at $\sim$3~GPa. Overall, the pressure-induced changes in the profile of the {\bf E}$\| c$ conductivity spectrum are much enhanced above $\sim$3~GPa. We compare our results to those recently reported for ZrSiS in a quantitative manner.
