Morimoto Takahiro, Furusaki Akira, Nagaosa Naoto
Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
RIKEN Center for Emergent Matter Science (CEMS), Wako, Saitama 351-0198, Japan.
Phys Rev Lett. 2015 Apr 10;114(14):146803. doi: 10.1103/PhysRevLett.114.146803. Epub 2015 Apr 9.
Three-dimensional topological insulators of finite thickness can show the quantum Hall effect (QHE) at the filling factor ν=0 under an external magnetic field if there is a finite potential difference between the top and bottom surfaces. We calculate energy spectra of surface Weyl fermions in the ν=0 QHE and find that gapped edge states with helical spin structure are formed from Weyl fermions on the side surfaces under certain conditions. These edge channels account for the nonlocal charge transport in the ν=0 QHE which is observed in a recent experiment on (Bi_{1-x}Sb_{x}){2}Te{3} films. The edge channels also support spin transport due to the spin-momentum locking. We propose an experimental setup to observe various spintronics functions such as spin transport and spin conversion.
有限厚度的三维拓扑绝缘体在外部磁场下，若上下表面之间存在有限电势差，则在填充因子ν = 0时可表现出量子霍尔效应（QHE）。我们计算了ν = 0的量子霍尔效应中表面外尔费米子的能谱，发现在特定条件下，侧面的外尔费米子会形成具有螺旋自旋结构的带隙边缘态。这些边缘通道解释了最近在（Bi₁₋ₓSbₓ）₂Te₃薄膜实验中观察到的ν = 0量子霍尔效应中的非局域电荷输运。由于自旋 - 动量锁定，边缘通道也支持自旋输运。我们提出了一种实验装置，以观察各种自旋电子学功能，如自旋输运和自旋转换。
