论文标题
在分层磁性绝缘体MNBI2TE4中具有远距离相互作用的二维铁磁学
Two-dimensional ferromagnetism with long-range interactions in the layered magnetic topological insulator MnBi2Te4
论文作者
论文摘要
MNBI2TE4（MBT）是一种有前途的范德华层层状抗铁磁（AF）拓扑绝缘子，它结合了拓扑非平凡的BI-TE带隙与铁磁性（FM）层（FM）层。我们对共对准的单晶进行非弹性中子散射（INS），以研究MBT中的磁相互作用。与以前的工作一致，我们发现AF Interlayer交换耦合和单轴磁各向异性具有可比的强度，这支持了允许在应用场中访问不同磁对称性的元磁过渡。二维内层FM旋转波的建模需要引入远程和竞争的海森堡FM和AF相互作用，至少是第七个最近的邻居，并且具有异常的阻尼，尤其是在布里群区域边界附近。第一原理的绝缘MBT计算发现，层间和内磁相互作用均已长期范围。我们讨论了在MBT的磁性中散装$ n $ type充电器和化学障碍发挥的潜在作用。
MnBi2Te4(MBT) is a promising van der Waals layered antiferromagnetic (AF) topological insulator that combines a topologically non-trivial inverted Bi-Te band gap with ferromagnetic (FM) layers of Mn ions. We perform inelastic neutron scattering (INS) on co-aligned single crystals to study the magnetic interactions in MBT. Consistent with previous work, we find that the AF interlayer exchange coupling and uniaxial magnetic anisotropy have comparable strength, which supports metamagnetic transitions that allow access to different magnetic symmetries in applied fields. Modelling of the two-dimensional intralayer FM spin waves requires the introduction of long-range and competing Heisenberg FM and AF interactions, up to at least the seventh nearest-neighbor, and possess anomalous damping, especially near the Brillouin zone boundary. First-principles calculations of insulating MBT find that both interlayer and intralayer magnetic interactions are long-ranged. We discuss the potential roles that bulk $n$-type charger carriers and chemical disorder play in the magnetism of MBT.
