论文标题
在两个阶梯网络中的本地化，运输和边缘状态在一个大交错的磁场中
Localization, transport and edge states in a two-strand ladder network in an aperiodically staggered magnetic field
论文作者
论文摘要
我们研究了在Aubry-André-Harper轮廓后，由外部磁场扰动的两臂紧密梯子的光谱和运输特性。被困在连续梯子中的变化磁通量模拟了轴向扭曲，使我们能够原则上探测从色带霍夫斯塔特几何形状到螺旋DNA链的各种系统。我们使用晶格哈密顿量的直接对角线化进行了深入的数值分析，以研究模型的电子光谱和传输特性。我们表明，这样的几何形状在能量景观中创造了自相似的多型模式。使用状态的局部密度分析光谱特性，并采用绿色的功能形式主义来获得两端传输概率。借助标准的多重分析分析以及对反参与率的评估，我们表明，该系统具有临界和扩展相，以缓慢变化的通量的逐渐变化，表明可能具有迁移率边缘。最后，我们报告了拓扑边缘模式的签名，这些标志与给予最近的邻居跳跃积分的相关扰动发现相关。我们的结果在涉及类似梯子的量子网络的实验中可能非常重要，在光学陷阱设置中用冷原子实现。
We investigate the spectral and transport properties of a two-arm tight-binding ladder perturbed by an external magnetic field following an Aubry-André-Harper profile. The varying magnetic flux trapped in consecutive ladder-cells simulates an axial twist that enables us, in principle, to probe a wide variety of systems ranging from a ribbon Hofstadter geometry to helical DNA chains. We perform an in-depth numerical analysis, using a direct diagonalization of the lattice Hamiltonian to study the electronic spectra and transport properties of the model. We show that such a geometry creates a self-similar multifractal pattern in the energy landscape. The spectral properties are analyzed using the local density of states and a Green's function formalism is employed to obtain the two-terminal transmission probability. With the standard multifractal analysis and the evaluation of inverse participation ratio we show that, the system hosts both critical and extended phase for a slowly varying aperiodic sequence of flux indicating a possible mobility edge. Finally, we report signatures of topological edge modes that are found to be robust against a correlated perturbation given to the nearest neighbor hopping integrals. Our results can be of importance in experiments involving ladder-like quantum networks, realized with cold atoms in an optical trap setup.
