论文标题
非热音调拓扑带隙
Non-Hermitian tuned topological band gap
论文作者
论文摘要
材料的外部可控的带隙性质对于设计具有所需属性的光电设备至关重要。在这里，研究了通过在原本琐碎的绝缘子中引入线性增益来对微不足道拓扑带隙进行单参数调整的可能性。将增益选择性地注入二聚体的一维晶格中，以便在空间内的空间内，而不是在时间倒转下，所得的非热汉密尔顿人是对称的。晶格的反转对称性呈现，以探测与散装Zak相关的Zak阶段的散装对应关系和拓扑不变性。分析表明，当增益参数跨非弱点退化时，在分析中表明，拓扑至不平凡的相位过渡和受保护边缘状态的出现发生。讨论了通过改变增益分布的边界和内部边界内部位置的可调性。在INGAASP半导体腔阵列的现实设计中，报道了增益控制的拓扑边缘状态的确认。
Externally controllable band gap properties of a material is crucial in designing optoelectronic devices with desirable properties on-demand. Here, a possibility of single parameter tuning of trivial to non-trivial topological band gap by the introduction of linear gain in an otherwise trivial insulator is investigated. Gain is selectively injected into a one dimensional lattice of dimers such that the resulting non-Hermitian Hamiltonian is symmetric under space-inversion but not under time-reversal. Inversion-symmetry of the lattice renders to probe the bulk-boundary correspondence and topological invariance by the bi-orthogonal Zak phase associated with a bulk Hamiltonian. Topological trivial to nontrivial phase transition and emergence of protected edge states are analytically shown to occur when the gain parameter is tuned across a non-Hermitian degeneracy. Tuneability of edge state location both at the boundary and inside the bulk by altering the gain distribution is discussed. Confirmation of gain-controlled topological edge state is reported in a realistic design of InGaAsP semiconductor cavity array.
