Atomic and electronic structures of FeSe monolayer and bilayer thin films on SrTiO3 (001): First-principles study
Atomic and electronic structures of FeSe monolayer and bilayer thin films on SrTiO3 (001): First-principles study
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SrTiO3 (001) 上 FeSe 单层和双层薄膜的原子和电子结构：第一性原理研究
DOI：
10.1103/physrevb.85.235123
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发表时间：
2012-06-14
影响因子：
3.7
通讯作者：
Xiang, Tao
中科院分区：
文献类型：
--
作者：
Liu, Kai;Lu, Zhong-Yi;Xiang, Tao
采用第一性原理计算方法研究了以SrO或TiO_2为终端的FeSe单层和双层薄膜的原子和电子结构。我们发现，无论是FeSe单层和双层的终端表现得像一个轻微的掺杂半导体与共线反铁磁秩序的Fe离子。FeSe通过偶极-偶极相互作用粘附到SrTiO 3表面。费米面主要是Fe-3d轨道的贡献。主要由TiO 2层中的O-2 p轨道贡献的价带位于费米能级以下，费米能级可以在少量掺杂空穴时变得导电。对于电子掺杂的SrTiO 3（001）与TiO 2终端，费米能级和FeSe单层的能带移动到衬底的能带隙。
By using first-principles calculations, we have studied the atomic and electronic structures of FeSe monolayer and bilayer thin films on SrTiO3 (001) with SrO or TiO2 termination. We find that both FeSe monolayer and bilayer on either termination behave like a slightly doped semiconductor with a collinear antiferromagnetic order on Fe ions. FeSe is adhered to the SrTiO3 surface by a dipole-dipole interaction. The Fermi surface is mainly of the contribution of Fe-3d orbitals. The valence band contributed mainly by the O-2p orbitals in the TiO2 layer is located slightly below the Fermi level, which can become conducting upon a small doping of holes. For electron-doped SrTiO3 (001) with TiO2 termination, the Fermi level and the energy bands of the FeSe monolayer shift into the energy band gap of the substrate.