论文标题
半迪拉克纳米替比的量子厅研究
Quantum Hall studies of a Semi-Dirac Nanoribbon
论文作者
论文摘要
在这里，我们使用近来开发的基于kernel多项式方法的新空间实现了Kubo公式的实际空间实现，在垂直磁场中全面研究了半迪拉克纳米替比的Landau水平，Hofstadter Butterfly和运输特性。 Dirac Ribbon被认为可以比较和对比半迪拉克系统的结果。我们发现，对于半迪拉克案例，兰道水平彼此不符合（对于狄拉克也是如此），与越野奶粉系统相反，能量带的平坦度在散装中消失，并且对于半迪拉克色带的分散性。对于外部字段的中间值，此功能最明显。 We further compute the longitudinal ($σ_{xx}$ and $σ_{yy}$) and the transverse or Hall ($σ_{xy}$) conductivities where the Hall conductivity shows a familiar quantization, namely, $σ_{xy} \propto 2n$ (the factor `2' includes the spin degeneracy) which is highly distinct from a Dirac system, such as graphene.由于分散异常在两个不同的纵向方向上，因此我们还观察到磁通型的各向异性行为。我们的研究可能对单层磷烯具有重要的影响。
Here we comprehensively investigate Landau levels, Hofstadter butterfly and transport properties of a semi-Dirac nanoribbon in a perpendicular magnetic field using a recently developed real-space implementation of the Kubo formula based on Kernel Polynomial Method. A Dirac ribbon is considered to compare and contrast our results for a semi-Dirac system. We find that the Landau levels being non-equidistant from each other for the semi-Dirac case (true for a Dirac as well), the flatness of the energy bands vanishes in the bulk and becomes dispersive for a semi-Dirac ribbon in contrast to a Dirac system. This feature is most discernible for intermediate values of the external field. We further compute the longitudinal ($σ_{xx}$ and $σ_{yy}$) and the transverse or Hall ($σ_{xy}$) conductivities where the Hall conductivity shows a familiar quantization, namely, $σ_{xy} \propto 2n$ (the factor `2' includes the spin degeneracy) which is highly distinct from a Dirac system, such as graphene. We also observe anisotropic behavior in magneto-transport in a semi-Dirac ribbon owing to the dispersion anomalies in two different longitudinal directions. Our studies may have important ramifications for monolayer phosphorene.
