Two-dimensional charge order stabilized in clean polytype heterostructures
Suk Hyun Sung, Noah Schnitzer, Steve Novakov, Ismail El Baggari, Xiangpeng Luo, Jiseok Gim, Nguyen M. Vu, Zidong Li, Todd B. Brintlinger, Yu Liu, Wenjian Lu, Yu… 展开作者
Suk Hyun Sung, Noah Schnitzer, Steve Novakov, Ismail El Baggari, Xiangpeng Luo, Jiseok Gim, Nguyen M. Vu, Zidong Li, Todd B. Brintlinger, Yu Liu, Wenjian Lu, Yuping Sun, Parag Deotare, Kai Sun, Liuyan Zhao, Lena F. Kourkoutis, John T. Heron, Robert Hovden
Compelling evidence suggests distinct correlated electron behavior may exist only in clean 2D materials such as 1T-TaS2. Unfortunately, experiment and theory suggest that extrinsic disorder in free standing 2D layers disrupts correlation-driven quantum behavior. Here we demonstrate a route to realizing fragile 2D quantum states through endotaxial polytype engineering of van der Waals materials. The true isolation of 2D charge density waves (CDWs) between metallic layers stabilizes commensurate long-range order and lifts the coupling between neighboring CDW layers to restore mirror symmetries via interlayer CDW twinning. The twinned-commensurate charge density wave (tC-CDW) reported herein has a single metal--insulator phase transition at ~350 K as measured structurally and electronically. Fast in-situ transmission electron microscopy and scanned nanobeam diffraction map the formation of tC-CDWs. This work introduces endotaxial polytype engineering of van der Waals materials to access latent 2D ground states distinct from conventional 2D fabrication.
Realization of polytype heterostructures via delicate structural transitions from a doped-Mott insulator
School of Physics, Renmin University of China（中国人民大学物理学院）；Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-nano Devices, School of Physics, Renmin University of China（中国人民大学物理学院光电功能材料与微纳器件北京市重点实验室）；Institute of Physics, Chinese Academy of Sciences（中国科学院物理研究所）
Interfacial thermal transport in Si/SiC and SiC/diamond heterostructures: effects of amorphous interlayers and SiC polytypes
K. N. Toosi University of Technology（K.N.托辛理工大学）；Institute for Research in Fundamental Sciences（基础科学研究所）；Imam Khomeini International University（伊玛目霍梅尼国际大学）
Topochemically-engineered coexistence of charge and spin orders in intercalated endotaxial heterostructures
University of California, Berkeley（加州大学伯克利分校）；Molecular Foundry, Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室分子发现中心）；Jawaharlal Nehru Centre for Advanced Scientific Research（贾瓦哈拉尔·尼赫鲁高级科学研究中心）；Max-Planck-Institute for Chemical Physics of Solids（马克斯·普朗克固体化学物理研究所）
Designer three-dimensional electronic bands in asymmetric transition metal dichalcogenide heterostructures
Monash University（蒙纳士大学）；University of Manchester（曼彻斯特大学）；Syarif Hidayatullah State Islamic University Jakarta（雅加达希达亚图拉国立伊斯兰大学）；Flinders University（弗林德斯大学）；Tohoku University（东北大学）；Lawrence Berkeley National Laboratory（劳伦斯伯克利国家实验室）；Pennsylvania State University（宾夕法尼亚州立大学）
Ferroelectric switching of interfacial dipoles in $α$-RuCl$_3$/graphene heterostructure
Daegu Gyeongbuk Institute of Science and Technology (DGIST)（大邱庆北科学技术院）；Pohang University of Science and Technology（浦项科技大学）；Institute for Basic Science（基础科学研究院）；National Institute for Materials Science（国立材料研究所）；California Institute of Technology（加州理工学院）
Quasicrystalline 30° Twisted Bilayer Graphene as an Incommensurate Superlattice with Strong Interlayer Coupling
层间耦合可用于设计范德华异质结构（超晶格）的电子结构，以获得单一材料中不可能的特性。到目前为止，异质结构的研究一直集中在具有长程莫尔周期的公度超晶格上。具有旋转对称性但不具有平移对称性的无公度异质结构（类似于准晶）不仅在自然界中罕见，而且由于缺乏相位相干性，层间相互作用通常被认为是可以忽略的。本文报道了在Pt（111）衬底上成功生长的准晶态30°扭曲双层石墨烯（30°-tBLG），并揭示了其电子结构。低能电子衍射和1383 cm $^{-1}$处的谷间双共振喇曼模式证实了30°-tBLG。此外，每个石墨烯层的布里渊区内部镜像狄拉克锥的出现以及区边界处的间隙开口表明这两个石墨烯层经由广义Umklapp散射机制耦合，即一个石墨烯层中的狄拉克锥通过另一个石墨烯层的倒易晶格矢量的散射。我们的工作突出了层间耦合在无公度准晶超晶格中的重要作用，从而将能带结构工程扩展到无公度超结构。
Coexistence of Chiral Majorana Edge States and Bogoliubov Fermi Surfaces in Two-Dimensional Nonsymmorphic Dirac Semimetal/Superconductor Heterostructures
A single-projection three-dimensional reconstruction algorithm for scanning transmission electron microscopy data
对三维纳米结构的兴趣增加，推动了能够在纳米级或纳米级以下三维成像的电子显微镜技术。我们提出了一种重建算法，作为输入的一个焦点系列的四维扫描透射电子显微镜（4D-STEM）数据。我们将该方法应用于铅铱酸盐，铅$_2$铱$_2$ O $_7$，钇稳定的氧化锆，Y $_{0.095}$ Zr $_{0.905}$ O $_2$，异质结构从数据采集与样品在一个单一的平面视图取向，沿光束方向堆叠的外延层。我们表明，Pb-Ir原子柱是可见的重建体积的最上层。我们比较这种方法的替代技术的深度切片使用微分相衬扫描透射电子显微镜（DPC-STEM）和多层重叠关联重建。
