论文标题
扩展的Su-Schrieffer-Heeger模型的非热概括
Non-Hermitian generalizations of extended Su-Schrieffer-Heeger models
论文作者
论文摘要
分析了具有较高时期的跳高系数（称为SSH3和SSH4模型）的Su-Schrieffer-Heeger（SSH）模型的非热概括。 Hermitian SSH3模型的常规结构构造失败了，但是由于复杂平面上的点间隙，非热概括导致拓扑系统。因此，非热式SSH3模型具有缠绕数，并表现出非铁皮皮肤效应。此外，SSH3模型具有两种类型的局部状态和与特殊对称性相关的零能量状态。 SSH3模型的总ZAK阶段显示量化，其有限值表明两种类型的局部状态共存。同时，SSH4模型类似于SSH模型，其非铁概括也表现出非铁皮皮肤效应。对具有不同边界条件的非热式SSH4模型的仔细分析表明，借助广义的布里鲁因区域或真实空间绕组数恢复了散装的对应关系。非热SSH3和SSH4模型的物理学可以在冷原子或其他模拟器中进行测试。
Non-Hermitian generalizations of the Su-Schrieffer-Heeger (SSH) models with higher periods of the hopping coefficients, called the SSH3 and SSH4 models, are analyzed. The conventional construction of the winding number fails for the Hermitian SSH3 model, but the non-Hermitian generalization leads to a topological system due to a point gap on the complex plane. The non-Hermitian SSH3 model thus has a winding number and exhibits the non-Hermitian skin effect. Moreover, the SSH3 model has two types of localized states and a zero-energy state associated with special symmetries. The total Zak phase of the SSH3 model exhibits quantization, and its finite value indicates coexistence of the two types of localized states. Meanwhile, the SSH4 model resembles the SSH model, and its non-Hermitian generalization also exhibits the non-Hermitian skin effect. A careful analysis of the non-Hermitian SSH4 model with different boundary conditions shows the bulk-boundary correspondence is restored with the help of the generalized Brillouin zone or the real-space winding number. The physics of the non-Hermitian SSH3 and SSH4 models may be tested in cold-atom or other simulators.
