Article
Chemistry, Multidisciplinary
Tianchao Niu, Miao Zhou
Summary: Boron, the lightest metalloid element, has similar characteristics to carbon in planar and cage molecules. Recent studies have focused on the various structures of mono- and bi-layer boron and their potential applications in materials science. This review highlights the latest achievements in the epitaxial growth of bilayer borophene on noble metal surfaces, discussing the roles of substrate and growth conditions. Bilayer borophene exhibits superior properties compared to single-layer borophene, but its synthesis remains challenging and requires further research.
Review
Chemistry, Multidisciplinary
Dechun Zhou, Heping Li, Nan Si, Hui Li, Harald Fuchs, Tianchao Niu
Summary: 2D materials have attracted attention for their unique properties since the discovery of graphene, with monoelemental 2D materials standing out for their superior synthetic exploration, excellent mobility, and wide range of band gaps. Efforts have been devoted to fabricating high-quality materials and revealing growth mechanisms in atomic scale.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Physics, Applied
Nemanja Peric, Corentin Durand, Maxime Berthe, Yan Lu, Kekeli N'Konou, Roland Coratger, Isabelle Lefebvre, Philipp Ebert, Louis Biadala, Ludovic Desplanque, Xavier Wallart, B. Grandidier
Summary: The knowledge of band alignment in semiconductor heterostructures is important for device performance. In this study, the direction of current flow in In0.53Ga0.47As/InP heterostructure nanowires was controlled, and the band offsets at the buried heterointerface were directly measured using low temperature multiple-probe tunneling spectroscopy. The results indicate the formation of an interface with a quality comparable to two-dimensional In0.53Ga0.47As/InP heterostructures.
APPLIED PHYSICS LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Mohammad Fazel Vafadar, Songrui Zhao
Summary: This study reports the use of radio-frequency plasma-assisted molecular beam epitaxy to achieve selective area epitaxy (SAE) of gallium nitride (GaN) nanowires at low substrate temperatures. The researchers successfully controlled the top-surface morphology of the nanowires through low temperature epitaxy. The results of this work will benefit the development of a fully controllable nanophotonic platform for various photonic devices.
ACS APPLIED NANO MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Heping Li, Dechun Zhou, Qingyuan He, Nan Si, Benwu Xin, Saiyu Bu, Qingmin Ji, Hui Li, Harald Fuchs, Tianchao Niu
Summary: This study presents the epitaxial growth of two phases of atomically thin SnSb on a Cu2Sb surface alloy and explores their rich physics and semiconductor properties. Through scanning tunneling microscopy characterizations and theoretical calculations, the atomic structures and theoretical properties of the most stable H-phase are revealed. The results suggest that 2D SnSb with intriguing properties has great potential for electronics research on an atomically thin platform.
Article
Chemistry, Multidisciplinary
Sisheng Duan, Jing-Yang You, Jian Gou, Jie Chen, Yu Li Huang, Meizhuang Liu, Shuo Sun, Yihe Wang, Xiaojiang Yu, Li Wang, Yuan Ping Feng, Yi-yang Sun, Andrew T. S. Wee, Wei Chen
Summary: This study reports the growth of single-layer iron germanide kagome nanoflakes and reveals the electronic localization of the kagome flat bands using scanning tunneling microscopy/spectroscopy. First-principles calculations demonstrate the topological nature and edge mode of the observed kagome materials.
Article
Chemistry, Physical
Shigeru Kaku, Kota L. Hiwatari, Junji Yoshino
Summary: By optimizing the surface cleaning procedures and growth conditions, we investigated the surface structure of strained-alpha-Sn layers grown on InSb(001) surfaces, revealing that the (2 x 2) diffraction patterns are attributed to double domain (2 x 1) reconstructed surfaces rotated 90 degrees with respect to each other.
APPLIED SURFACE SCIENCE
(2022)
Article
Multidisciplinary Sciences
Haifeng Lv, Caiyun Chen, Wenbin Li, Zhiwen Zhuo, Peng Cheng, Yi-Qi Zhang, Baojie Feng, Kehui Wu, Xiaojun Wu, Lan Chen
Summary: In this study, unique B5 clusters were successfully formed on a monolayer borophene (MLB) on a Cu(111) surface using molecular beam epitaxy and scanning tunneling microscopy experiments. The B5 clusters selectively bind to specific sites of MLB with covalent boron-boron bonds in a periodic arrangement. The close-packed adsorption of B5 clusters facilitates the synthesis of bilayer borophene, exhibiting a domino effect-like growth mode. The successful growth and characterization of uniform boron clusters on a surface enrich the boron-based nano-materials and reveal the essential role of small clusters during the growth of borophene.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Review
Physics, Applied
Cheng-Long Xue, Shao-Chun Li
Summary: The review discusses the structure and electronic properties of monolayer antimony, focusing on theoretical calculations and experimental achievements for both alpha- and beta-phases. Insights are also provided for further exploring the appealing properties of antimonene and materials with analogous structures.
JAPANESE JOURNAL OF APPLIED PHYSICS
(2021)
Article
Chemistry, Physical
Adem Yavuz, M. Fatih Danisman
Summary: We studied the vibrational properties and the effect of beam kinetic energy on PFP thin films grown by SMBD technique. We found significant differences in the properties of films grown using helium and argon carrier gasses for low coverage films and low deposition rates. However, for multilayer films, there were no significant differences between films grown with helium and argon. The vibrational properties were investigated using s-SNOM, and it was found that PFP-substrate interactions resulted in significant differences in the spectra of thin films but not thick films. Davydov splitting of the IR modes was observed for both thin and thick films, indicating similar molecular arrangements.
APPLIED SURFACE SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Chinedu Christian Ahia, Ngcali Tile, Edson L. Meyer, Johannes Reinhardt Botha
Summary: High resolution X-ray diffraction, scanning probe microscopy, scanning electron microscopy, and optical microscopy were used to evaluate the crystallinity and morphology of epitaxial layers of InSb deposited on GaSb substrate. The study showed that the thickness and quality of the deposited InSb layers are highly sensitive to changes in growth temperatures and V/III ratios, regardless of the Sb source used. Additionally, XRD patterns indicated an improvement in crystallinity for InSb layers deposited using TMSb compared to TDMASb.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Chemistry, Multidisciplinary
Yusong Bai, Tao Jian, Zemin Pan, Jinghao Deng, Xiaoyu Lin, Chao Zhu, Da Huo, Zhengbo Cheng, Yong Liu, Ping Cui, Zhenyu Zhang, Qiang Zou, Chendong Zhang
Summary: We experimentally explore the charge-density wave (CDW) phases in monolayer NbTe2 and discover the presence of 4x4, 4x1, 28x28, and 19x19 phases. These findings are supported by a comprehensive growth phase diagram established through material synthesis and scanning tunneling microscope characterization. Surprisingly, the energetically stable phase is the larger-scale 19x19 phase, contradicting the prior prediction of the 4x4 phase.
Article
Chemistry, Multidisciplinary
Rui Li, Jin-Hua Nie, Jing-Jing Xian, Jian-Wang Zhou, Yan Lu, Mao-Peng Miao, Wen-Hao Zhang, Ying-Shuang Fu
Summary: The growth of ultrathin films with molecular beam epitaxy allows for the construction of CrTe3-CrTe2 planar heterojunctions. Vacuum annealing transforms CrTe3 into CrTe2, which can be controlled by annealing time. We also identified a superstructure composed of hybrid units of CrTe3 and CrTe2. This study provides a foundation for building spintronic circuits and engineering electronic states in artificial superlattice structures.
Article
Engineering, Electrical & Electronic
A. Alzeidan, T. F. Cantalice, K. D. Vallejo, R. S. R. Gajjela, A. L. Hendriks, P. J. Simmonds, P. M. Koenraad, A. A. Quivy
Summary: The performance of infrared photodetectors based on submonolayer quantum dots was investigated as a function of the arsenic flux. Despite a reduction in the density of such nanostructures with decreasing arsenic flux, all devices showed similar figures of merit and a very high specific detectivity.
SENSORS AND ACTUATORS A-PHYSICAL
(2022)
Article
Chemistry, Physical
Zizhao Liu, Ye Tao, Zhiqiang Cui, Yi Ji, Xuhan Zhou, Peigen Li, Yunwei Zhang, Dingyong Zhong
Summary: This study reports a novel two-dimensional tetragonal structure of vanadium telluride (VTe). The atomic structures and electronic properties of 2D VTe with a V:Te ratio of 1:1 were characterized by scanning tunneling microscopy and first-principles calculations. The metallic feature of VTe and the itinerant nature of electrons near the Fermi energy were revealed.
Article
Physics, Multidisciplinary
T. Valla, P. Pervan, I Pletikosic, I. K. Drozdov, Asish K. Kundu, Zebin Wu, G. D. Gu
Summary: The study demonstrates the important role of anti-ferromagnetic spin fluctuations in producing attractive interactions between electrons in high-temperature cuprate superconductors. The connection between superconductivity and spin fluctuations is crucial, especially at the overdoped end point. In some materials, a Lifshitz transition may coincide with this point, leading to a loss of large momentum anti-ferromagnetic fluctuations.
Article
Multidisciplinary Sciences
Lingyuan Kong, Lu Cao, Shiyu Zhu, Michal Papaj, Guangyang Dai, Geng Li, Peng Fan, Wenyao Liu, Fazhi Yang, Xiancheng Wang, Shixuan Du, Changqing Jin, Liang Fu, Hong-Jun Gao, Hong Ding
Summary: Iron-based superconductors are promising platforms for Majorana zero modes, but sample inhomogeneity poses challenges for practical construction of topological qubits. By studying LiFeAs superconductor, researchers discovered Majorana zero modes in impurity-assisted vortices due to tuning of bulk Dirac fermions, offering an ideal material platform for topological quantum computation.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Li Geng, Guo Hui, Gao Hong-Jun
Summary: Compared with three-dimensional materials, two-dimensional materials exhibit superior properties in terms of electronics, optics, thermics, and mechanics due to their reduced dimensionality. Fabricating materials under ultra-high vacuum has advantages and is widely adopted in the growth of 2D materials.
ACTA PHYSICA SINICA
(2022)
Article
Chemistry, Physical
Zhipeng Song, Juxia Yi, Jing Qi, Qi Zheng, Zhili Zhu, Lei Tao, Yun Cao, Yan Li, Zhaoyan Gao, Ruizi Zhang, Li Huang, Geng Li, Ziqiang Xu, Xu Wu, Yeliang Wang, Chengmin Shen, Yu-Yang Zhang, Hongliang Lu, Xiao Lin, Shixuan Du, Hong-Jun Gao
Summary: This study reports the formation of line defects in monolayer titanium selenide (TiSe2) and their application in catalysis. The research demonstrates that TiSe2 with line defects exhibits good catalytic activity, especially for the hydrogen evolution reaction (HER). Moreover, defects decorated with single Pt atoms show enhanced catalytic activity.
Article
Multidisciplinary Sciences
Hui Chen, Haitao Yang, Bin Hu, Zhen Zhao, Jie Yuan, Yuqing Xing, Guojian Qian, Zihao Huang, Geng Li, Yuhan Ye, Sheng Ma, Shunli Ni, Hua Zhang, Qiangwei Yin, Chunsheng Gong, Zhijun Tu, Hechang Lei, Hengxin Tan, Sen Zhou, Chengmin Shen, Xiaoli Dong, Binghai Yan, Ziqiang Wang, Hong-Jun Gao
Summary: In this study, unconventional superconductivity and a pair density wave (PDW) were observed in CsV3Sb5, a vanadium-based kagome metal. The material exhibits a V-shaped pairing gap and a 3Q PDW, along with other unique characteristics such as strong-coupling superconductivity and charge order. These findings provide insights into the correlated electronic states and superconductivity in vanadium-based kagome metals.
Article
Multidisciplinary Sciences
Hui Li, Zengyi Du, Ze-Bin Wu, Daniel Putzky, Sang Hyun Joo, Asish K. Kundu, Xiaotao Xu, Xiaoyan Shi, Jinho Lee, Abhay N. Pasupathy, Gennady Logvenov, Bernhard Keimer, Tonica Valla, Ivan Bozovic, Ilya K. Drozdov, Kazuhiro Fujita
Summary: In this study, we used Spectroscopic Imaging Scanning Tunneling Microscopy (SI-STM) to investigate a DyBa2Cu3O7-delta (DBCO) thin film. We observed a peculiar transfer of spectral weight within the superconducting gap, which could be controlled at the nanoscale by manipulating the tip-sample distance and junction resistance. The results suggest that the interaction between the STM tip and the sample alters the electronic configurations in the film, possibly due to intrinsic band bending and tip-induced band bending at the interface between the surface and the bulk.
SCIENTIFIC REPORTS
(2022)
Article
Nanoscience & Nanotechnology
Rongting Wu, Ze-Bin Wu, Ivan Bozovic
Summary: The article discusses the process of atomic-layer-by-layer deposition of magnesium on a copper surface by molecular beam epitaxy, leading to the formation of a new 2D Mg2Cu material with non-trivial topology of electron bands. This material is seen as a promising platform for studying new topological states of matter.
ADVANCED ELECTRONIC MATERIALS
(2022)
Review
Physics, Multidisciplinary
Geng Li, Shiyu Zhu, Peng Fan, Lu Cao, Hong-Jun Gao
Summary: Researchers have discovered Majorana zero modes (MZMs) in iron-based superconductors, which overcomes the difficulty of constructing complex hybrid artificial structures to observe pure MZMs. MZMs have been observed in various iron-based superconductors, and researchers have conducted studies and observations using scanning tunneling microscopy and other techniques.
Article
Multidisciplinary Sciences
Geng LjD, Haitao YangLE, Peijie Jiang, Cong Wang, Qiuzhen Cheng, Shangjie Tian, Guangyuan Han, Chengmin Shen, Xiao Lin, Hechang Lei, Wei Ji, Ziqiang Wang, Hong-Jun Gao
Summary: This study reports the discovery of a novel unidirectional charge density wave (CDW) order on the surface of chiral crystal CoSi, which is a unique Weyl semimetal with unconventional chiral fermions. The CDW is incommensurate with lattice momentum and crystalline symmetry directions, and exhibits a pi phase shift in the layer stacking direction. The tunneling spectrum shows an energy gap that modulates spatially with the CDW wave vector.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Yadong Gu, Menghu Zhou, Mengdi Zhang, Yanwei Wu, Binbin Ruan, Xingyuan Hou, Fan Zhang, Peijie Jiang, Qingsong Yang, Geng Li, Mingwei Ma, Genfu Chen, Lei Shan, Zhian Ren
Summary: In this study, a one-step synthesis method was reported to grow high-quality Fe(Te,Se) single crystals through minor Mn doping. The as-grown centimeter-sized crystals showed bulk superconductivity with sharp electrical resistivity and magnetic susceptibility transitions, and large specific heat jumps. Moreover, the optimally doped sample exhibited significantly enhanced upper critical field and large self-field critical current density.
SCIENCE CHINA-MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Zhao-Yan Gao, Wenpeng Xu, Yixuan Gao, Roger Guzman, Hui Guo, Xueyan Wang, Qi Zheng, Zhili Zhu, Yu-Yang Zhang, Xiao Lin, Qing Huan, Geng Li, Lizhi Zhang, Wu Zhou, Hong-Jun Gao
Summary: This study reports the synthesis of atomic monolayer Si9C15 on Ru (0001) and Rh(111) substrates. By employing scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), and density functional theory (DFT) calculations, the researchers reveal that Si9C15 possesses a buckled honeycomb structure as a two-dimensional lattice, with good air stability and a bandgap of approximately 1.9 eV. This finding expands the library of 2D materials and offers a promising platform for future studies in nanoelectronics and nanophotonics.
ADVANCED MATERIALS
(2022)
Article
Multidisciplinary Sciences
Meng Li, Geng Li, Lu Cao, Xingtai Zhou, Xiancheng Wang, Changqing Jin, Ching-Kai Chiu, Stephen J. Pennycook, Ziqiang Wang, Hong-Jun Gao
Summary: By using scanning tunneling microscopy/spectroscopy, an ordered and tunable Majorana zero mode (MZM) lattice has been discovered in naturally strained LiFeAs superconductor. This finding provides a new pathway for future topological quantum computation.
Article
Materials Science, Multidisciplinary
Asish K. Kundu, Tufan Roy, Santanu Pakhira, Ze-Bin Wu, Masahito Tsujikawa, Masafumi Shirai, D. C. Johnston, Abhay N. Pasupathy, Tonica Valla
Summary: In this study, the electronic structure of YbMg2Bi2 and CaMg2Bi2 materials was investigated in detail. The experimental results show that CaMg2Bi2 material has significantly smaller Fermi surface and Fermi velocity, and the Yb-4f states in YbMg2Bi2 material have negligible impact on transport properties. The calculations reveal that both materials belong to the Z(2) topological class.
NPJ QUANTUM MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Peng Fan, Hui Chen, Xingtai Zhou, Lu Cao, Geng Li, Meng Li, Guojian Qian, Yuqing Xing, Chengmin Shen, Xiancheng Wang, Changqing Jin, Genda Gu, Hong Ding, Hong-Jun Gao
Summary: We demonstrate the manipulation of Abrikosov vortices on the surfaces of Fe(Te,Se) and LiFeAs by utilizing one-dimensional wrinkles and low-temperature scanning tunneling microscopy/spectroscopy (STM/S). The wrinkles trap the Abrikosov vortices induced by the external magnetic field, and we are able to tailor and manipulate the wrinkles using an STM tip. Surprisingly, we show that the pinned vortices move together with these wrinkles even at high magnetic field up to 6 T. This work provides a universal and effective method for manipulating wrinkle-pinned vortices and simultaneously measuring the local density of states on the surfaces of iron-based superconductors.
Article
Materials Science, Multidisciplinary
Gu Zhang, Chuang Li, Geng Li, Xin Liu, Can-Li Song, Fu-Chun Zhang, Dong E. Liu
Summary: It is predicted that a vortex in a topological superconductor contains a Majorana zero mode (MZM). However, confirming the Majorana signature is easily disrupted by various interruptions. To overcome these interruptions, a novel Majorana hunting protocol is proposed, which relies on dissipation introduced by disorders at the sample-substrate interface. This protocol highlights three features that provide strong evidence for identifying MZM.
