论文标题
在平等不变的费米表面的半量化大厅效应
Half-Quantized Hall Effect at the Parity-Invariant Fermi Surface
论文作者
论文摘要
在二维中，凝结的物质实现了一个迪拉克锥是一个长期存在的问题。在这里，我们报告了在磁性拓扑绝缘子异质结构中发现的单个无间隙迪拉克锥的半量化大厅电导。它表明，当奇偶对称性在费米表面附近不变时，在单位E^{2}/h中将霍尔电导在单位中进行了半量度。无间隙的狄拉克点是稳定的，并受到局部平价对称性和拓扑绝缘体的拓扑非平凡带结构的保护。在最近的一个实验中观察到的一半霍尔电导[Mogi等，Nat。物理。 18，390（2022）]归因于无间隙狄拉克锥的存在。结果表明，具有一半拓扑结构的拓扑阶段的凝结物质实现。
Condensed matter realization of a single Dirac cone of fermions in two dimensions is a long-standing issue. Here we report the discovery of a single gapless Dirac cone of half-quantized Hall conductance in a magnetically-doped topological insulator heterostructure. It demonstrates that the Hall conductance is half-quantized in the unit e^{2}/h when the parity symmetry is invariant near the Fermi surface. The gapless Dirac point is stable and protected by the local parity symmetry and the topologically nontrivial band structure of the topological insulator. The one-half Hall conductance observed in a recent experiment [Mogi et al, Nat. Phys. 18, 390 (2022)] is attributed to the existence of the gapless Dirac cone. The results suggest a condensed matter realization of a topological phase with a one-half topological invariant.
