论文标题
Kekulé诱导山谷双折射和石墨烯中的偏斜散射
Kekulé Induced Valley Birefringence and Skew Scattering in Graphene
论文作者
论文摘要
在石墨烯中，kekulé-y键纹理修饰了电子带结构，产生了两个同心狄拉克锥，其在互相空间中的γ点中具有不同的费米速度。能量分散在给定能量下导致每个同胞蛋白成分的不同组速度。这种能谱与P-N连接中的负折射指数相结合，允许在石墨烯中出现光学双折射的电子类似物。我们用散射方法表征了由圆形对称的kekulé图案和门控区域产生的山谷双折射。我们发现苛性剂在空间中分离的两个尖缘，其距离取决于Kekulé相互作用，并提供了其强度的量度。然后，在低载体浓度下，我们发现了一个非变化偏斜的横截面，显示了电子周围的电子散射的不对称性。这种效果与山谷大厅效应的出现有关，因为具有相反山谷极化的电子偏向相反的方向。
In graphene, a Kekulé-Y bond texture modifies the electronic band structure generating two concentric Dirac cones with different Fermi velocities lying in the Γ-point in reciprocal space. The energy dispersion results in different group velocities for each isospin component at a given energy. This energy spectrum combined with the negative refraction index in p-n junctions, allows the emergence of an electronic analog of optical birefringence in graphene. We characterize the valley birefringence produced by a circularly symmetric Kekulé patterned and gated region using the scattering approach. We found caustics with two cusps separated in space by a distance dependent on the Kekulé interaction and that provides a measure of its strength. Then, at low carrier concentration we find a non-vanishing skew cross section, showing the asymmetry in the scattering of electrons around the axis of the incoming flux. This effect is associated with the appearance of the valley Hall effect as electrons with opposite valley polarization are deflected towards opposite directions.
