论文标题

多原子条纹晶格中电子的补偿量子和拓扑厅效应

Compensated Quantum and Topological Hall Effects of Electrons in Polyatomic Stripe Lattices

论文作者

Göbel, Börge, Mook, Alexander, Henk, Jürgen, Mertig, Ingrid

论文摘要

通常将量子大厅的效应理解为自由电子气体,其中样品边缘的拓扑保护的边缘状态(LLS)形成了导电通道。在周期性的晶体中,LLS印有晶格性能。横向大厅电导率中的高原在能量上不再等距。在此,考虑了具有多原子基础的晶体。对于不同原子的条纹排列,频带结构在非试验中求解并表现出强烈的振荡,形成具有很小带镜的显着图案。霍尔电导率强烈降低了这些带中的能量,只有尖峰仍能在间隙中的能量。这些效果可追溯到初始带结构中的开放轨道。相应的LLS由具有正质量和负质量的状态形成。横向电荷电导率的部分取消也适用于不同的多原子晶格,即使磁场被拓扑上的非平凡自旋纹理取代。在存在磁性天空的情况下,拓扑厅效应被抑制。讨论与霍夫史塔特蝴蝶和轨道磁化的计算相辅相成。

The quantum Hall effect is generally understood for free electron gases, in which topologically protected edge states between Landau levels (LLs) form conducting channels at the edge of the sample. In periodic crystals, the LLs are imprinted with lattice properties; plateaus in the transverse Hall conductivity are not equidistant in energy anymore. Herein, crystals with a polyatomic basis are considered. For a stripe arrangement of different atoms, the band structure resorts nontrivially and exhibits strong oscillations that form a salient pattern with very small bandgaps. The Hall conductivity strongly decreases for energies within these bands, and only sharp peaks remain for energies in the gap. These effects are traced back to open orbits in the initial band structure; the corresponding LLs are formed from states with positive and negative effective mass. The partial cancellation of transverse charge conductivity also holds for different polyatomic stripe lattices and even when the magnetic field is replaced by a topologically nontrivial spin texture. The topological Hall effect is suppressed in the presence of magnetic skyrmions. The discussion is complemented by calculations of Hofstadter butterflies and orbital magnetization.

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