Park Jungmin, Oh Inseon, Jin Mi-Jin, Jo Junhyeon, Choe Daeseong, Yun Hyung Duk, Lee Suk Woo, Lee Zonghoon, Kwon Soon-Yong, Jin Hosub, Chung Suk Bum, Yoo Jung-Woo
School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan, 44919, Republic of Korea.
Center for Scientific Instrumentation, Division of Scientific Instrumentation & Management, Korea Basic Science Institute, Daejeon, 34133, Korea.
Sci Rep. 2020 Mar 16;10(1):4784. doi: 10.1038/s41598-020-61481-6.
The pristine graphene described with massless Dirac fermion could bear topological insulator state and ferromagnetism via the band structure engineering with various adatoms and proximity effects from heterostructures. In particular, topological Anderson insulator state was theoretically predicted in tight-binding honeycomb lattice with Anderson disorder term. Here, we introduced physi-absorbed Fe-clusters/adatoms on graphene to impose exchange interaction and random lattice disorder, and we observed Anderson insulator state accompanying with Kondo effect and field-induced conducting state upon applying the magnetic field at around a charge neutral point. Furthermore, the emergence of the double peak of resistivity at ν = 0 state indicates spin-splitted edge state with high effective exchange field (>70 T). These phenomena suggest the appearance of topological Anderson insulator state triggered by the induced exchange field and disorder.
用无质量狄拉克费米子描述的原始石墨烯可以通过各种吸附原子的能带结构工程以及异质结构的近邻效应呈现拓扑绝缘体状态和铁磁性。特别是，在具有安德森无序项的紧束缚蜂窝晶格中理论上预测了拓扑安德森绝缘体状态。在此，我们在石墨烯上引入了物理吸附的铁簇/吸附原子以施加交换相互作用和随机晶格无序，并且我们在电荷中性点附近施加磁场时观察到伴随近藤效应和场致导电状态的安德森绝缘体状态。此外，在ν = 0状态下电阻率双峰的出现表明具有高效应交换场（>70 T）的自旋分裂边缘状态。这些现象表明由诱导交换场和无序触发的拓扑安德森绝缘体状态的出现。
