Generalized Aubry-André-Harper model with p -wave superconducting pairing
Generalized Aubry-André-Harper model with p -wave superconducting pairing
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DOI：
10.1103/physrevb.94.125408
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发表时间：
2016-07
影响因子：
3.7
通讯作者：
Q. Zeng;Shu Chen;R. Lu
中科院分区：
文献类型：
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作者：
Q. Zeng;Shu Chen;R. Lu
我们研究了具有 $p$ 波超导配对的广义 Aubry-Andr'e-Harper (AAH) 模型。该系统中最近相邻晶格位点之间的跳跃幅度和位点电势均由周期为 $1/\ensuremath{\alpha}$ 的余弦函数调制。在不相称的情况下$[\ensuremath{\alpha}=\left(\sqrt{5}\ensuremath{-}1\right)/2]$，由于跳频幅度的调制，该准周期系统的临界区域显着减小，系统变得更容易从扩展态转变为局域态。在相应的情况$(\ensuremath{\alpha}=1/2)$中，我们发现当我们调整系统参数时，该模型显示出三个不同的阶段：类Su-Schrieffer-Heeger (SSH)的平凡阶段、类SSH的拓扑阶段和类Kitaev的拓扑阶段。这项工作给出了这些相的相图和拓扑量子数。这种与超导配对相结合的广义AAH模型为我们研究从扩展态到安德森局域态的相变以及不同拓扑相之间的转变提供了一个有用的试验场。
We investigate a generalized Aubry-Andr\'e-Harper (AAH) model with $p$-wave superconducting pairing. Both the hopping amplitudes between the nearest-neighboring lattice sites and the on-site potentials in this system are modulated by a cosine function with a periodicity of $1/\ensuremath{\alpha}$. In the incommensurate case $[\ensuremath{\alpha}=\left(\sqrt{5}\ensuremath{-}1\right)/2]$, due to the modulations on the hopping amplitudes, the critical region of this quasiperiodic system is significantly reduced and the system becomes easier to be turned from extended states to localized states. In the commensurate case $(\ensuremath{\alpha}=1/2)$, we find that this model shows three different phases when we tune the system parameters: Su-Schrieffer-Heeger (SSH)-like trivial, SSH-like topological, and Kitaev-like topological phases. The phase diagrams and the topological quantum numbers for these phases are presented in this work. This generalized AAH model combined with superconducting pairing provides us with a useful test field for studying the phase transitions from extended states to Anderson localized states and the transitions between different topological phases.