论文标题
来自抗铁磁铁拓扑 - 绝缘子异质结构的异常磁电机光学效应
Anomalous Magneto Optic Effects from an Antiferromagnet Topological-Insulator Heterostructure
论文作者
论文摘要
没有净磁化的材料通常不是磁性的活性。尽管这对于共线抗铁磁铁（AFM）和拓扑绝缘子（TI）是正确的，但此处显示出，当Ti和Afm膜接近耦合时，磁光线KERR效应（moke）出现。由于缺乏宏观磁化，AFM只对Ti表面之一的旋转耦合，破坏了时间反转和反转对称性，这导致了微小的$μ$ gg moke信号。通过优化基板上的AFM和Ti膜厚度，可以通过5个数量级轻松地通过5个数量级来增强这种小摩克。对于稍微离子的结构，可以通过改变费米能量来电气打开6度的Kerr旋转。这需要少于20 MEV，这对于低功率旋转型和磁磁体设备来说是令人鼓舞的。我们进一步表明，这种简单的结构很容易弹性到5％的材料生长误差。
Materials with no net magnetization are generally not magneto-optically active. While this is individually true for a collinear antiferromagnet (AFM) and a topological insulator (TI), it is shown here that the magneto-optic Kerr effect (MOKE) emerges when the TI and AFM films are proximity coupled. Because of the lack of macroscopic magnetization, the AFM only couples to the spin of one of the TI's surfaces breaking time-reversal and inversion symmetry -- which leads to a tiny $μ$deg MOKE signal. This small MOKE can be easily enhanced by 5 orders of magnitude, via cavity resonance, by optimizing the AFM and TI film thicknesses on the substrate. For slightly off-resonant structures, a 6 deg Kerr rotation can be electrically switched on by varying the Fermi energy. This requires less than 20 meV, which is encouraging for low power spintronics and magneto-optic devices. We further show that this simple structure is easily resilient to 5% material growth error.
