任意填充下广义Rice-Mele模型中的量子化极化
Quantized polarization in a generalized Rice-Mele model at arbitrary filling
AI总结：
本研究针对广义Rice-Mele模型在任意填充下的电荷极化展开，发现其受组合对称性约束呈量子化且仅由填充决定，分解极化的体与边缘贡献并验证其与能隙的关系，还推广模型探讨了反演对称保护的边缘模式。
摘要：
我们讨论了作为一维电荷有序系统模型的广义Rice-Mele模型在每个格点任意粒子填充下的电荷极化。该模型既不具备传统的键中心反演对称性，也不单独具备单格点平移对称性，但拥有这些对称性的组合形式。我们证明，基态中的电荷极化受该组合对称性约束而呈现量子化特性，且仅由填充因子表征。特别地，在零填充极限下，极化可以为1/2（模1）。在开边界条件下，无论是否存在边缘模式，系统边缘附近都会积累过剩电荷。相应地，我们将极化分解为体贡献和边缘贡献，并通过数值模拟证明，当能隙较大（较小）时，极化由前者（后者）主导。我们还讨论了该模型的一种简单推广形式，通过引入电荷极化的晶胞内和晶胞间贡献，研究了受反演对称性保护的无能隙边缘模式的存在与否。
英文摘要：
We discuss the charge polarization in a generalized Rice-Mele model at arbitrary particle filling per site as a model of charge ordered systems in one dimension. The model possesses neither the conventional bond-centered inversion symmetry nor the one site translation symmetry alone, but has combinations of these symmetries. We show that the charge polarization in the ground state is quantized by the combined symmetry and is characterized solely by the filling. Especially, the polarization can be $1/2$ (mod 1) in the zero filling limit. Under the open boundary condition, there exist excess charges accumulated near edges of the system irrespective of existence or absence of edge modes. Correspondingly, we decompose the polarization into a bulk contribution and an edge contribution, and numerically demonstrate that the polarization is dominated by the former (latter) when the energy gap is large (small). We also discuss a simple generalization of our model and examine absence/existence of a gapless edge mode protected by the inversion symmetry by introducing intra unit cell and inter unit cell contributions of the charge polarization.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
