论文标题
铁磁 - 电极诱导的霍尔效应在拓扑狄拉克半学
Ferromagnetic-electrodes-induced Hall effect in topological Dirac semimetals
论文作者
论文摘要
我们提出了具有铁磁电极的拓扑狄拉克半学中的非常规类型的大厅效应。拓扑狄拉克半学本身具有时间反向对称性，而附着的铁磁电极会损坏它，从而导致大厅的响应。这种诱导的霍尔效应是螺旋表面/边缘状态的特征，该状态在拓扑材料中出现，例如拓扑狄拉克半学或量子自旋霍尔绝缘子。我们使用具有四末端几何形状的晶格模型来计算霍尔电导/电阻和霍尔角。对于具有四个电极的拓扑狄拉克半学，无论电流电极还是电压电极都是铁磁剂，都会发生诱导的霍尔效应。当电极中的旋转几乎完全极化时，霍尔角就会与量子大厅的状态或理想的磁性Weyl半学的角度大。我们显示了诱导的大厅对杂质的鲁棒性，还讨论了自旋注射和旋转衰减问题。该大厅的响应可用于检测两个铁磁电极的磁化是平行还是反平行的。
We propose an unconventional type of Hall effect in a topological Dirac semimetal with ferromagnetic electrodes. The topological Dirac semimetal itself has time-reversal symmetry, whereas attached ferromagnetic electrodes break it, causing the large Hall response. This induced Hall effect is a characteristic of the helical surface/edge states that arise in topological materials, such as topological Dirac semimetals or quantum spin Hall insulators. We compute the Hall conductance/resistance and the Hall angle by using a lattice model with four-terminal geometry. For topological Dirac semimetals with four electrodes, the induced Hall effect occurs whether the current electrodes or the voltage electrodes are ferromagnetic. When the spins in electrodes are almost fully polarized, the Hall angle becomes as large as that of quantum Hall states or ideal magnetic Weyl semimetals. We show the robustness of the induced Hall effect against impurities and also discuss the spin injection and spin decay problems. This Hall response can be used to detect whether the magnetizations of the two ferromagnetic electrodes are parallel or antiparallel.
