Engineering of octahedral rotations and electronic structure in ultrathin SrIrO3 films
Engineering of octahedral rotations and electronic structure in ultrathin SrIrO3 films
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超薄 SrIrO3 薄膜中的八面体旋转和电子结构工程
DOI：
10.1103/physrevb.101.085101
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发表时间：
2020-02-03
影响因子：
3.7
通讯作者：
Pan, X. Q.
中科院分区：
文献类型：
--
作者：
Guo, W.;Ji, D. X.;Pan, X. Q.
层状钙钛矿铱酸盐SrIrO 4与高T-c铜酸盐有许多相似之处，并有望拥有新的超导电性，但从未在实验上实现。尽管有相似之处，突出的IrO 6八面体旋转和相当大的净斜反铁磁力矩躺在每个IrO 2平面在Sr 2 IrO 4是惊人的不同，从高的T-C铜酸盐的八面体旋转和净斜矩小得多或可以忽略不计。在这里，使用反应分子束外延，我们证明了八面体旋转周围的面内和面外轴在外延铱酸盐薄膜可以抑制一步一步通过界面夹紧施加立方衬底作为膜接近二维极限。原位角分辨光电子能谱和第一性原理计算表明，在1-和2-晶胞厚SrIrO 3膜，提供理想的单层和双层类比的高T-C铜酸盐的带隙的反铁磁基态与分散的低洼带。
Layered perovskite iridate SrIrO4 shares many similarities with high T-c cuprates and is expected to host novel superconductivity but has never been realized experimentally. Despite the similarities, the prominent IrO6 octahedral rotations and sizable net canted antiferromagnetic moments lying in each IrO2 plane in Sr2IrO4 are strikingly different from high T-c cuprates where the octahedral rotations and net canted moment are much smaller or negligible. Here, using reactive molecular beam epitaxy, we demonstrate that the octahedral rotations around the in-plane and out-of-plane axes in epitaxial iridate films can be suppressed step-by-step via interfacial clamping imposed by cubic substrates as the films approach the two-dimensional limit. In situ angle-resolved photoemission spectroscopy and first-principles calculations show a gapped antiferromagnetic ground state with dispersive low-lying bands in 1- and 2-unit-cell-thick SrIrO3 films, providing ideal single- and bilayer analogies of high T-c cuprates.