论文标题
由渗透量子旋转厅状态引起的持续电流和自旋扭矩
Persistent currents and spin torque caused by percolated quantum spin Hall state
论文作者
论文摘要
在最近的实验中，我们通过紧密结合模型和线性响应理论研究了2D拓扑绝缘子/铁磁金属平面连接中的量子自旋霍尔状态。我们证明，边缘状态狄拉克锥是否被淹没到铁磁子带中，而磁化强度的方向显着影响（i）边缘状态如何将其渗透到铁磁铁中，以及（ii）边缘状态的自旋孔锁定。室温的层流层流持续电荷和界面附近的旋转电流被发现。另外，发现在杂质附近，在2D拓扑绝缘子边缘的电流诱导的自旋极化迅速增强。当前诱导的在铁磁铁中诱导的自旋两极化主要是在平面外向$ {\ hat {\ bf z}} $上极化，呈现出一种当前诱导的自旋扭矩，主要是字段，类似于场的$ \ propto {\ bf s}} \ hat fips {\ hat fips {\ hat {\ hat {\ hat {\ bf z} $ {\ bf z}}。
Motivated by recent experiments, we investigate the quantum spin Hall state in 2D topological insulator/ferromagnetic metal planar junctions by means of a tight-binding model and linear response theory. We demonstrate that whether the edge state Dirac cone is submerged into the ferromagnetic subbands and the direction of the magnetization dramatically affect (i) how the edge state percolates into the ferromagnet, and (ii) the spin-momentum locking of the edge state. Laminar flows of room temperature persistent charge and spin currents near the interface are uncovered. In addition, the current-induced spin polarization at the edge of the 2D topological insulator is found to be dramatically enhanced near the impurities. The current-induced spin polarization in the ferromagnet is mainly polarized in the out-of-plane direction ${\hat{\bf z}}$, rendering a current-induced spin torque that is predominantly field-like $\propto {\bf S}\times{\hat{\bf z}}$.
