发表机构
University of Minnesota; California Institute of Technology; Massachusetts Institute of Technology; Hankuk University of Foreign Studies; Technical University of Denmark; University of Antwerpen; Temple University; University of Illinois, Urbana-Champaign; Helmholtz-Zentrum Berlin für Materialien und Energie GmbH; Kyung Hee University（明尼苏达大学; 加州理工学院; 麻省理工学院; 韩国外国语大学; 丹麦技术大学; 安特卫普大学; 天普大学; 伊利诺伊大学厄巴纳-香槟分校; 柏林亥姆霍兹材料与能源中心; 庆熙大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过扭转SrTiO3薄膜构建准晶氧化物界面，实现八重和十二重对称的准周期有序，并揭示其电子重构与非线性光学响应。
AI 中文摘要
准晶揭示了长程有序可以在没有平移周期性的情况下存在，但设计强键合准晶界面的确定性路线仍未探索。在此，我们展示了通过在牺牲层上外延生长SrTiO3薄膜、释放薄膜、按预定角度扭转并将其键合到选定衬底上，可以工程化此类界面。扭转45°的SrTiO3双层形成具有八重旋转对称性的八角准晶界面，而依次旋转30°组装的三层则形成具有十二重对称性的十二角界面。选区电子衍射和纳米束电子衍射、多层电子叠层成像、原子分辨暗场成像、傅里叶分析和实空间铺砌确立了长程准晶有序，退火后的电子能量损失谱显示出电子重构。基于机器学习原子间势的原子模拟表明，当双层扭转角接近45°时，八角有序出现。在1.5 nm扭转双层中的偏振依赖X射线吸收谱揭示了扭转依赖的电子响应，太赫兹场诱导的二次谐波产生圆二色性在45°准晶条件下识别出对称依赖的非线性光学响应。因此，扭转氧化物薄膜提供了一条可扩展的途径，用于工程化准周期有序并将其与复杂氧化物中的界面键合、轨道重构和非线性光学响应耦合。
英文摘要
Quasicrystals reveal that long-range order can exist without translational periodicity, but deterministic routes for designing strongly bonded quasicrystalline interfaces remain unexplored. Here, we show that such interfaces can be engineered by growing epitaxial SrTiO3 membranes on a sacrificial layer, releasing them, twisting them by prescribed angles, and bonding them onto a chosen substrate. SrTiO3 bilayers twisted by 45° form an octagonal quasicrystalline interface with eight-fold rotational symmetry, whereas trilayers assembled with successive 30° rotations form a dodecagonal interface with twelve-fold symmetry. Selected-area and nano-beam electron diffraction, multislice electron ptychography, atomic-resolution dark field imaging, Fourier analysis, and real-space tiling establish long-range quasicrystalline order with electronic reconstruction evident from electron energy-loss spectroscopy after annealing. Atomistic simulations based on machine-learned interatomic potentials show that octagonal order emerges as the bilayer twist angle approaches 45°. Polarization-dependent X-ray absorption spectroscopy in 1.5 nm twisted bilayers reveals a twist-dependent electronic response, and terahertz-field-induced second-harmonic generation circular dichroism identifies a symmetry-dependent nonlinear optical response at the 45° quasicrystalline condition. Twisted oxide membranes therefore provide an extendable route to engineer quasiperiodic order and couple it to interfacial bonding, orbital reconstruction, and nonlinear optical response in complex oxides.
Comments26 pages, 4 figures
