论文标题
通过宏观磁性屏障从2D拓扑绝缘子的边缘状态形成结合状态
Formation of bound states from the edge states of 2D topological insulator by macroscopic magnetic barriers
论文作者
论文摘要
来自2D拓扑绝缘子的离域边缘状态的结合状态形成模型是通过考虑附着在HGTE/CDTE量子边缘的磁性屏障的影响来得出的。所得结构具有1D量子点的空间形式，其结合态数的变化取决于屏障参数。边缘状态与屏障之间交换相互作用的空间曲线来自与单个杂质磁矩的相互作用，并将其推广到由杂质集合形成的屏障结构。将所得的哈密顿量作为屏障参数（包括其强度和磁矩方向）的函数进行了研究。结果表明，对于两个屏障的平行磁化，无论屏障强度如何，都会形成至少两个离散水平。对于反平行磁化，至少要为屏障的任何强度形成单个界面。我们的结果可能有助于设计基于拓扑绝缘体的新型量子点。
A model of bound state formation from the delocalized edge states of 2D topological insulator is derived by considering the effects of magnetic barriers attached to the edge of the HgTe/CdTe quantum well. The resulting structure has a spatial form of 1D quantum dot with variable number of bound states depending on barrier parameters. The spatial profile of exchange interaction between the edge states and barriers is derived from the interaction with single impurity magnetic moment and is generalized for the barrier bulk structure formed by ensemble of impurities. The resulting Hamiltonian is studied as a function of barrier parameters including their strength and orientation of the magnetic moments. It is shown that for parallel magnetization of two barriers at least two discrete levels are formed regardless of the barrier strength. For antiparallel magnetization at least a single bound state is formed for any strength of the barriers. Our results may help in design of novel types of quantum dots based on topological insulators.
