论文标题
EUO/MGO（001）超晶格的Chern绝缘阶段和热电特性
Chern insulating phases and thermoelectric properties of EuO/MgO(001) superlattices
论文作者
论文摘要
（EUO）$ _ {n} $/（MGO）$ _ {m} $（001）超级晶格（SLS）的拓扑和热电性能是使用密度功能理论计算探索的，包括Hubbard $ u $ u $ u $ u $ u $ term fors lob u $ u $ term forboltzmann运输理论。在（euo）$ _ {1} $/（mgo）$ _ {3} $（001）sl在MGO的晶格常数下方，由于占用的EU $ 4F $ 4F $ 4F $ 4F $ 5D $ 5D $ 5D $ 5D $ 5D $ 4F的摩擦式耦合（SOC），Spin-Or-Orbit耦合（SOC）的巨大频段差距为0.51 eV。相反奇偶校验的乐队之间的这种反转伴随着沿$γ$点周围的带交叉轮廓的自旋纹理的自旋重新定位，并导致$ c $ = -1的Chern绝缘子，也得到了单个边缘状态的确认。此外，这个Chern绝缘阶段显示出有希望的热电特性，例如Seebeck系数在400至800 $μ$ vk $^{ - 1} $之间。类似的SOC诱导的频段反转也发生在Ferromagnetic Semimetallic（EUO）$ _ {2} $/（MGO）$ _ {2} $（001）SL中。尽管带有消失的带隙，但它导致了大量异常的霍尔电导率，值高达-1.04 $ e^{2}/h $，并且热电特性较低。这两个系统都强调了非平凡拓扑带和热电学之间的关系，也在反转对称性的系统中。
The topological and thermoelectric properties of (EuO)$_{n}$/(MgO)$_{m}$(001) superlattices (SLs) are explored using density functional theory calculations including a Hubbard $U$ term together with Boltzmann transport theory. In (EuO)$_{1}$/(MgO)$_{3}$(001) SL at the lattice constant of MgO a sizable band gap of 0.51 eV is opened by spin-orbit coupling (SOC) due to a band inversion between occupied localized Eu $4f$ and $5d$ conduction electrons. This inversion between bands of opposite parity is accompanied by a spin reorientation in the spin-texture along the contour of band crossing surrounding the $Γ$ point and leads to a Chern insulator with $C$=-1, also confirmed by the single edge state. Moreover, this Chern insulating phase shows promising thermoelectric properties, e.g. a Seebeck coefficient between 400 and 800 $μ$VK$^{-1}$. A similar SOC-induced band inversion takes place also in the ferromagnetic semimetallic (EuO)$_{2}$/(MgO)$_{2}$(001) SL. Despite the vanishing band gap, it leads to a substantial anomalous Hall conductivity with values up to -1.04 $e^{2}/h$ and somewhat lower thermoelectric properties. Both systems emphasize the relation between non-trivial topological bands and thermoelectricity also in systems with broken inversion symmetry.
