SmO thin films: A flexible route to correlated flat bands with nontrivial topology
SmO thin films: A flexible route to correlated flat bands with nontrivial topology
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SmO 薄膜：通过非平凡拓扑实现相关平带的灵活途径
DOI：
10.1103/physrevb.91.195127
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发表时间：
2015
影响因子：
3.7
通讯作者：
M. Haverkort
中科院分区：
文献类型：
--
作者：
D. Kasinathan;K. Koepernik;L. Tjeng;M. Haverkort
使用密度泛函理论为基础的计算，我们表明，相关的混合价化合物的SmO是一个三维强拓扑半金属作为一个4f\text {\ensuremath{-}}5d$带反转的结果在$X$点。[001]表面Bloch谱密度揭示了两个弱相互作用的Dirac锥，它们在$\overline{M}$点处准边生成，另一个在$\overline{\mathrm{\ensurmath {\Gamma}$点处是单Dirac锥。我们还表明，在SMO的拓扑非平凡性是非常强大的，并普遍适用于广泛的晶格参数，使其成为一个理想的候选人，以调查拓扑非平凡相关的薄膜形式的平带。此外，电子填充是可调的应变。此外，我们发现的条件下，反演是4f\text {\ensuremath{-}}6s$类型，使SmO是一个相当独特的系统。SmO的晶体对称性和晶格常数与铁磁半导体EuO的相似性使得SmO/EuO薄膜界面成为实现强关联电子系统中量子反常霍尔效应的优秀竞争者。
Using density functional theory based calculations, we show that the correlated mixed-valent compound SmO is a three-dimensional strongly topological semimetal as a result of a $4f\text{\ensuremath{-}}5d$ band inversion at the $X$ point. The [001] surface Bloch spectral density reveals two weakly interacting Dirac cones that are quasidegenerate at the $\overline{M}$ point and another single Dirac cone at the $\overline{\mathrm{\ensuremath{\Gamma}}}$ point. We also show that the topological nontriviality in SmO is very robust and prevails for a wide range of lattice parameters, making it an ideal candidate to investigate topological nontrivial correlated flat bands in thin-film form. Moreover, the electron filling is tunable by strain. In addition, we find conditions for which the inversion is of the $4f\text{\ensuremath{-}}6s$ type, making SmO to be a rather unique system. The similarities of the crystal symmetry and the lattice constant of SmO to the well studied ferromagnetic semiconductor EuO, makes SmO/EuO thin film interfaces an excellent contender towards realizing the quantum anomalous Hall effect in a strongly correlated electron system.