论文标题
二聚体链中拓扑边缘状态的光学和磁性特征
Optical and magnetic signatures of the topological edge states in a dimerised donor chain
论文作者
论文摘要
我们通过使用时间依赖性的Hartree-fock和密度功能理论研究了一维供体二聚体阵列的激发态。我们发现，调整支出间距离可以诱导从拓扑琐事的抗铁磁基态到支持自旋极化边缘状态的拓扑相的拓扑相变。该过渡伴随着光谱的重大变化，为相换和存在边缘状态提供了签名；边缘状态导致$ 1S \ rightarrow 2p $原子过渡。相比之下，链的大部分变得无旋，从而诱导了homo-lumo间隙的减少，并且光谱中的激发能的降低。除了Su-Schrieffer-Heeger-Heeger-Heebard模型（远程电子相关性和1S歧管以上的基础状态）之外的物理学外，还包含了对结果的关键作用，并导致了与拓扑相过渡相关的光学响应变化的新预测。我们的结果为在半导体中使用人工供体线性阵列提供了理论基础，以设计形成拓扑边缘状态。
We have studied the excited states of a one-dimensional donor dimer array by using time-dependent Hartree-Fock and density-functional theories. We find that tuning the inter-donor distances can induce a topological phase transition from a topologically trivial anti-ferromagnetic ground state to a topological phase supporting spin-polarised edge states. Significant changes in the optical spectra accompany this transition, providing signatures for the phase transition and the existence of the edge state; the edge states lead to a robust $1s\rightarrow 2p$ atomic transition. By contrast, the bulk of the chain becomes spinless, inducing a reduction in the HOMO-LUMO gap and a decrease of the excitation energies in the optical spectra. The inclusion of physics beyond the Su-Schrieffer-Heeger-Hubbard model (long-range electron correlations and basis states beyond the 1s manifold) has a critical effect on the results and leads to the novel prediction of a change in optical response related to a topological phase transition. Our results provide a theoretical foundation for using artificial donor linear arrays in semiconductors to form topological edge states by design.
