论文标题
Hofstadter Butterfly和Twisted Double Bileayer石墨蛋白的量子大厅效应
Hofstadter butterfly and the quantum Hall effect in twisted double bilayer graphenes
论文作者
论文摘要
我们研究了均匀磁场中扭曲的双双层石墨烯的能量光谱和量子厅效应。我们研究了两种不同的排列，即AB-AB和AB-BA，它们在相对方向上有所不同，但在没有磁场的情况下具有非常相似的带结构。对于每个系统，我们通过使用满足磁译本条件的连续性汉密尔顿，计算每个光谱间隙处的能量光谱和量化霍尔电导率。我们表明，即使它们的零磁场带结构非常相似，AB-AB和AB-BA堆栈的Hofstadter蝴蝶光谱也有很大差异。 AB-AB的频谱具有谷化的变性，可以通过施加层间势不对称来提高，而AB-BA的频谱在任何情况下都没有这种堕落性。我们从晶格对称性和乐队拓扑的角度来解释差异的起源。
We study the energy spectrum and quantum Hall effects of the twisted double bilayer graphene in uniform magnetic field. We investigate two different arrangements, AB-AB and AB-BA, which differ in the relative orientation but have very similar band structures in the absence of a magnetic field. For each system, we calculate the energy spectrum and quantized Hall conductivities at each spectral gap by using a continuum Hamiltonian that satisfies the magneto-translation condition. We show that the Hofstadter butterfly spectra of AB-AB and AB-BA stackings differ significantly, even though their zero magnetic field band structures closely resemble; the spectrum of AB-AB has valley degeneracy, which can be lifted by applying interlayer potential asymmetry, while the spectrum of AB-BA has no such degeneracy in any case. We explain the origin of the difference from the perspectives of lattice symmetry and band topology.
