论文标题
$α-\ Mathcal {t} _3 $带有弯曲的“平面”频段的材料的动力学电导率
Dynamical optical conductivity for gapped $α-\mathcal{T}_3$ materials with a curved "flat" band
论文作者
论文摘要
我们已经计算了$α-\ Mathcal {t} _3 $材料的动力学电导率。这是一种特殊的能量分散类型，因为对于所有$α-\ Mathcal {t} _3 $带有带隙的材料，除了石墨烯和骰子晶格限制外，平面频带将接收非零分散体并假定弯曲形状。也取消了扁平能带的无限$ {\ bf k} $ - 也解除了平面能带的变性。如果$α-\ MATHCAL {T} _3 $材料通过圆形偏振光辐射，则可以获得这种低能带结构。我们已经计算了零温度和有限温度的光导率，以及有限且近使掺杂的情况。我们已经证明，对于所有类型的$α-\ Mathcal {t} _3 $材料，可以原理获得分析表达式，并为间隙骰子晶格提供了封闭形式的分析表达式。我们的数值结果揭示了$α-\ Mathcal {t} _3 $和硅和有两个非等效带镜的一些众所周知的光导率的特征，并且展示了一些以前在任何现有的狄拉克材料中都没有发现的非常具体的特征。
We have calculated the dynamical optical conductivity for $α-\mathcal{T}_3$ materials in the presence of a finite bandgap in their energy bandstructure. This is a special type of energy dispersions because for all $α-\mathcal{T}_3$ materials with a bandgap, except graphene and a dice lattice limits, the flat band receives a non-zero dispersion and assumes a curved shape. The infinite ${\bf k}$-degeneracy of the flat energy band is also lifted. Such a low-energy bandstructure could be obtained if an $α-\mathcal{T}_3$ material is irradiated off-resonant with circularly polarized light. We have calculated the optical conductivity for the zero and finite temperatures, as well as for the cases of a finite and nearly-zero doping. We have demonstrated that analytical expressions could be in principle obtained for all types of gapped $α-\mathcal{T}_3$ materials and provided the closed-form analytical expressions for a gapped dice lattice. Our numerical results reveal some well-known signatures of the optical conductivity in $α-\mathcal{T}_3$ and silicene with two non-equivalent bandgaps, as well as demonstrate some very specific features which have not been previously found in any existing Dirac materials.
