论文标题
扰动的平带中的关键隔离器过渡和分形边缘
Critical-to-Insulator Transitions and Fractality Edges in Perturbed Flatbands
论文作者
论文摘要
我们研究了准碘扰动对一维全机式晶格模型的影响。这样的网络可以通过通过角度$θ_i$参数为参数的局部统一变换的有限序列对角度化。在没有一般性的情况下，我们专注于带有带隙$δ$的两个频段的情况。弱扰动会导致有效的哈密顿量，其依赖于$θ_i$的对基因和偏离的准二级术语。对于某些角度值，有效模型与扩展的Harper模型一致。通过改变Quasiperiodic电势的参数，\ iffalse和歧管角$θ_i$ \ fi，我们观察到局部绝缘状态和整个参数范围，托管具有宽带传输的关键状态。对于有限的准静脉电势强度，关键的构造过渡变成了能量取决于我们称与关键状态分离的分形边缘的差异。
We study the effect of quasiperiodic perturbations on one-dimensional all-bands-flat lattice models. Such networks can be diagonalized by a finite sequence of local unitary transformations parameterized by angles $θ_i$. Without loss of generality, we focus on the case of two bands with bandgap $Δ$. Weak perturbations lead to an effective Hamiltonian with both on- and off-diagonal quasiperiodic terms that depend on $θ_i$. For some angle values, the effective model coincides with the extended Harper model. By varying the parameters of the quasiperiodic potentials, \iffalse and the manifold angles $θ_i$ \fi we observe localized insulating states and an entire parameter range hosting critical states with subdiffusive transport. For finite quasiperiodic potential strength, the critical-to-insulating transition becomes energy dependent with what we term fractality edges separating localized from critical states.
