论文标题
在Srtio $ _3 $（001）上，无限层的电子重建与钙钛矿镍盐膜的基本差异（001）
Fundamental difference in the electronic reconstruction of infinite-layer vs. perovskite neodymium nickelate films on SrTiO$_3$(001)
论文作者
论文摘要
由SR掺杂NDNIO $ _2 $电影Srtio $ _3 $（001）[自然（伦敦）572，624（2019）中的SR掺杂ndnio $ _2 $的最新报道的动机，我们探索了极地界面在NDNIO $ _N $/srtio $ n = $ n = $ n = $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $ _3 $（001）上的作用第一原理计算，包括库仑排斥项。对于无限层镍膜（$ n = 2 $），电子重建使界面上二维电子气（2DEG）的出现令人惊讶，涉及涉及Ti $ 3D $状态的强大职业。 This effect is more pronounced than in LaAlO$_3$/SrTiO$_3$(001) and accompanied by a substantial reconstruction of the Fermi surface: a depletion of the self-doping Nd $5d$ states and an enhanced Ni $e_g$ orbital polarization reaching up to $35\%$ at the surface, reflecting a single hole in the $ 3D_ {X^2-Y^2} $状态，即类似铜的行为。相比之下，钙钛矿膜（$ n = 3 $）或单个钙钛矿层在接口处持续存在的二元形式。我们表明，从钙钛矿到无限层阶段的拓扑反应仅限于镍膜，而srtio $ _3 $底物仍然完好无损。
Motivated by recent reports of superconductivity in Sr-doped NdNiO$_2$ films on SrTiO$_3$(001) [Nature (London) 572, 624 (2019)], we explore the role of the polar interface on the structural and electronic properties of NdNiO$_n$/SrTiO$_3$(001) ($n=2,3$) by performing first-principles calculations including a Coulomb repulsion term. For infinite-layer nickelate films ($n=2$), electronic reconstruction drives the surprising emergence of a two-dimensional electron gas (2DEG) at the interface involving a strong occupation of the Ti $3d$ states. This effect is more pronounced than in LaAlO$_3$/SrTiO$_3$(001) and accompanied by a substantial reconstruction of the Fermi surface: a depletion of the self-doping Nd $5d$ states and an enhanced Ni $e_g$ orbital polarization reaching up to $35\%$ at the surface, reflecting a single hole in the $3d_{x^2-y^2}$ states, i.e., cuprate-like behavior. In contrast, no 2DEG forms for perovskite films ($n=3$) or if a single perovskite layer persists at the interface. We show that the topotactic reaction from the perovskite to the infinite-layer phase is confined to the nickelate film, whereas the SrTiO$_3$ substrate remains intact.
