论文标题
Semi-Dirac和Pseudospin-1模型的光学电导率：Zitterbewegung方法
Optical conductivity of semi-Dirac and pseudospin-1 models: Zitterbewegung approach
论文作者
论文摘要
我们提出了一种基于准粒子速度相关因子的评估来计算半迪拉克和伪胞素模型的光导率的方法，这些方法还描述了Zitterbewegung的现象。将此方法应用于半迪拉克模型，并通过合并狄拉克锥，间隙骰子和Lieb晶格模型，我们找到了光学纵向和霍尔电导率的精确分析表达式。对于半迪拉克模型，获得的表达式使我们能够分析频谱各向异性，范霍夫奇异性和狄拉克锥体在纵向电导率中的作用。此外，我们预测在低温下在直流运输中表现出的系统中拓扑相变的签名。对于骰子和Lieb晶格，我们强调了光谱间隙的作用，该频谱差距定义了与flat频带和从平面频段的过渡相关的频率阈值。
We present a method to calculate the optical conductivity of semi-Dirac and pseudospin models based on the evaluation of quasiparticle velocity correlators which also describe the phenomenon of zitterbewegung. Applying this method to the semi-Dirac model with merging Dirac cones and gapped dice and Lieb lattice models we find exact analytical expressions for optical longitudinal and Hall conductivities. For the semi-Dirac model the obtained expressions allow us to analyze the role of spectrum anisotropy, van Hove singularities and Dirac cones in longitudinal conductivity. In addition, we predict signatures of topological phase transition with changing gap parameter in such a system that are manifested in dc transport at low temperatures. For the dice and Lieb lattices we emphasize the role of spectral gap, which defines frequency thresholds related to transitions to and from flat band.
