Article
Chemistry, Multidisciplinary
Shawulienu Kezilebieke, Viliam Vano, Md N. Huda, Markus Aapro, Somesh C. Ganguli, Peter Liljeroth, Jose L. Lado
Summary: By using moire patterns in van der Waals materials, we have successfully achieved a topological superconducting state. The magnetic moire pattern gives rise to Yu-Shiba-Rusinov minibands and periodic modulation of the Majorana edge modes.
Article
Chemistry, Physical
Yin Yin, Guanyong Wang, Chen Liu, Haili Huang, Jiayi Chen, Jiaying Liu, Dandan Guan, Shiyong Wang, Yaoyii Li, Canhua Liu, Hao Zheng, Jinfeng Jia
Summary: A moire superlattice has been discovered in topological insulators, showing a periodic modulation on the electronic structure. This study demonstrates that the rotation angles between Sb2Te3 film and graphene substrate can be strongly influenced by substrate temperature, leading to different moire patterns with varying levels of complexity. Comparing dI/dV curves from Sb2Te3 films with different moire patterns suggests that the superstructure can provide degrees of freedom in modifying electronic structure, stimulating further research on the moire modulation in topological insulators.
Article
Materials Science, Multidisciplinary
Kun Xie, Pengju Li, Liangliang Liu, Runxiao Zhang, Yumin Xia, Haohao Shi, Desheng Cai, Yitong Gu, Limin She, Yeheng Song, Weifeng Zhang, Zhengyu Zhang, Yu Jia, Shengyong Qin
Summary: Researchers have successfully grown two-monolayer highly crystalline Pb1-xBix(111) films with controllable Bi concentrations x using molecular beam epitaxy and studied their structural and superconducting properties using scanning tunneling microscopy. They found that the superconducting transition temperatures of Pb1-xBix films exhibit a domelike behavior with increasing Bi concentration x. First-principles calculations revealed that Bi doping can promote the electronic states and the electron-phonon coupling strength at lower x, but suppress the electron-phonon coupling strength and superconductivity with largely Bi electronic states when Bi doping increases over a critical ratio. These findings not only demonstrate a quantum phenomenon of superconductivity in highly crystalline alloyed films but also provide a practical pathway to tune the superconductivity at the atomic level.
Article
Chemistry, Multidisciplinary
Caleb Z. Zerger, Linsey K. Rodenbach, Yi-Ting Chen, Benjamin Safvati, Morgan Z. Brubaker, Steven Tran, Tse-An Chen, Ming-Yang Li, Lain-Jong Li, David Goldhaber-Gordon, Hari C. Manoharan
Summary: This research demonstrates that the Cu(111) surface state under wafer-scale hBN is homogeneous in energy and spectral weight over nanometer length scales and across atomic terraces. However, a new spectral feature that is not observed on bare Cu(111) varies with atomic registry and shares the spatial periodicity of the hBN/Cu(111) moire.
Article
Chemistry, Multidisciplinary
Shuhui Li, Yu Wang, Peng Cheng, Baojie Feng, Lan Chen, Kehui Wu
Summary: The study demonstrates the growth of high-quality few-layer SnS thin films on mica and Nb-doped SrTiO3(100) substrates by molecular epitaxy growth, and the sulfurization of the top layer to form a monolayer SnS2, resulting in a high-quality SnS2/SnS 2D heterojunction with reversible heterojunction formation. Scanning tunneling spectroscopy measurements indicate a type-II band alignment in the SnS2/SnS heterostructure, showing promise for constructing artificial 2D heterojunctions with desired properties.
Article
Chemistry, Physical
Srdjan Stavric, Valeria Chesnyak, Simone del Puppo, Mirco Panighel, Giovanni Comelli, Cristina Africh, Zeljko Sljivancanin, Maria Peressi
Summary: The role of moire graphene superstructures in promoting confined adsorption of different metal atoms is investigated using density functional theory calculations and scanning-tunneling microscopy measurements. The results show that the moire pattern acts as a nanostructured template that confines single metal atoms and few atoms clusters on a 2D support. The confinement is selective and depends on the atomic species, with some preferring to adsorb on ridges and others on valleys. The selectivity also affects the diffusion of the adsorbates, resulting in unidirectional mass transport on the 2D support.
Article
Chemistry, Multidisciplinary
Kaihui Li, Feiping Xiao, Wen Guan, Yulong Xiao, Chang Xu, Jinding Zhang, Chenfang Lin, Dong Li, Qingjun Tong, Si-Yu Li, Anlian Pan
Summary: Moire superlattices exhibit a magnification effect and are sensitive to both external disturbances and internal atomic reconstructions. Long-wavelength WS2 superlattices can be reconstructed into various moire morphologies, ranging from regular hexagons to heavily deformed shapes. The interaction between external nonuniform heterostrain and intrinsic atomic reconstruction is responsible for this interesting evolution of moire structures.
Article
Chemistry, Multidisciplinary
Wenhui Li, Qian Gao, Yu Wang, Peng Cheng, Yi-Qi Zhang, Baojie Feng, Zhenpeng Hu, Kehui Wu, Lan Chen
Summary: In this study, it is demonstrated that few-layer gallium selenide (GaSe) grown on highly ordered pyrolytic graphite (HOPG) exhibits coexistence of quantum well states (QWS) and a two-dimensional electron gas (2DEG). The QWS are located in the valence bands and the 2DEG is located in the conduction bands. Additionally, monolayer GaSe/HOPG heterostructures with different stacking angles form distinct moire patterns that effectively modulate the electronic properties of GaSe.
Article
Nanoscience & Nanotechnology
N. Sarkar, P. R. Bandaru, R. C. Dynes
Summary: A methodology for testing the interlayer bonding strength of 2D surfaces and associated 1D and 2D surface defects using scanning tunneling microscope tip-induced deformation is demonstrated. The surface elastic deformation characteristics of soft 2D monatomic sheets such as graphene and graphite are found to be related to the underlying local bonding configurations. The surface deformation of 2D graphitic moire patterns reveals the varying inter-layer van der Waals strength across its domains. These findings contribute to the understanding of interlayer bonding strength in 1D grain boundaries and grains, as well as anomalous phenomena in probing 2D materials at small gap distances as a function of strain.
Article
Chemistry, Multidisciplinary
Jingfeng Li, Mahdi Ghorbani-Asl, Kinga Lasek, Vimukthi Pathirage, Arkady V. Krasheninnikov, Matthias Batzill
Summary: By locally modulating the interlayer atom coordination in the van der Waals heterostructure of PtSe2/PtTe2, a nanoscale electronic structure texture can be introduced in PtSe2. The interaction between PtSe2 and PtTe2 reduces the band gap of PtSe2. Density functional theory calculations indicate that variations in atom coordination in the moire unit cell cause differences in charge transfer and interface dipole.
Article
Chemistry, Multidisciplinary
Yohan Kim, Huijun Han, Da Luo, Rodney S. Ruoff, Hyung-Joon Shin
Summary: The structural and electronic properties of graphene grown on catalytic metal surfaces are significantly modified due to the interaction between graphene and the substrate. To minimize the influence of the metal substrate, NaCl thin films can be introduced as intercalation layers to decouple graphene from the metal substrate, resulting in quasi-freestanding graphene.
Article
Computer Science, Artificial Intelligence
Cong Yang, Zhenyu Yang, Yan Ke, Tao Chen, Marcin Grzegorzek, John See
Summary: This paper presents a simple and effective framework for extracting moire edge maps from images with moire patterns. The framework includes a strategy for generating training triplets and a Moire Pattern Detection Neural Network (MoireDet) for estimating moire edge maps. The design of three encoders in MoireDet utilizes both high-level contextual and low-level structural features of various moire patterns. Comprehensive experiments demonstrate the advantages of MoireDet: better identification precision on two datasets and a significant improvement over state-of-the-art demoireing methods.
IEEE TRANSACTIONS ON IMAGE PROCESSING
(2023)
Article
Chemistry, Multidisciplinary
Yuhiro Segawa, Kenji Yamazaki, Jun Yamasaki, Kazutoshi Gohara
Summary: A new method for measuring the 3D atomic structure of free-standing graphene ripples using TEM is proposed and experimentally validated. The specimen in the experiment was found to be moving upward, and the ripple was approximated as a composite of sinusoidal waves while measuring the time dependence of its height and lateral size.
Article
Chemistry, Physical
Tingwei Hu, Dong Yang, Haitao Gao, Yan Li, Xiangtai Liu, Kewei Xu, Qianfeng Xia, Fei Ma
Summary: The atomic structure and electronic properties of intercalated Pb atoms under graphene were investigated using STM/STS, revealing different moire patterns and sensitivity to tip scanning. PbG exhibits similar electronic states to free-standing graphene due to the shielding effects of Pb intercalation, with the crystallographic relationship confirmed by DFT calculations. This study provides insights into the structure of intercalated Pb atoms under graphene, potentially enabling the development of new 2D materials capped by graphene.
Article
Chemistry, Multidisciplinary
Chao Li, Jan Homberg, Alexander Weismann, Richard Berndt
Summary: The study reveals that AlPc molecules lose their spin moment on superconducting Pb(100) but molecular magnetism can be restored by surrounding molecules. Unlike other molecules, AlPc molecules have similar magnetic moments and lead to unusually high conductance peaks.
Article
Chemistry, Physical
Li -Juan Shi, Li-Zhen Yang, Jia-Qi Deng, Ling-Hui Tong, Qilong Wu, Li Zhang, Lijie Zhang, Long-Jing Yin, Zhihui Qin
Article
Chemistry, Physical
Xiao Guo, Qiwei Tian, Yongsong Wang, Jinxin Liu, Guiping Jia, Weidong Dou, Fei Song, Lijie Zhang, Zhihui Qin, Han Huang
Summary: Graphene nanoribbons (GNRs) are a potential alternative to graphene with gaps, and have been used in next-generation nanoelectronic devices. Research has found that temperature affects the frequency of G mode and RBLM, and the temperature coefficient of 7-AGNR is relatively high.
Article
Physics, Multidisciplinary
Ling-Hui Tong, Qingjun Tong, Li-Zhen Yang, Yue-Ying Zhou, Qilong Wu, Yuan Tian, Li Zhang, Lijie Zhang, Zhihui Qin, Long-Jing Yin
Summary: Recent studies have shown that twisted monolayer-bilayer graphene (TMBG) has a higher tunability and can host moire flat bands. Through scanning tunneling microscopy and spectroscopy, a direct comparison between TMBG and twisted bilayer graphene (TBG) is conducted, confirming the existence of flat electronic bands in TMBG. The bandwidth of the flat-band peak in TMBG is slightly narrower than that in TBG. Additionally, the flat-band states in TMBG exhibit a unique layer-resolved localization-delocalization coexisting feature.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Li-Zhen Yang, Ling-Hui Tong, Cheng-Sheng Liao, Qilong Wu, Xiaoshuai Fu, Yue-Ying Zhou, Yuan Tian, Li Zhang, Lijie Zhang, Meng-Qiu Cai, Lin He, Zhihui Qin, Long-Jing Yin
Summary: We present a controllable route to construct easily tunable flat bands in folded graphene by nano origami-controlled strain engineering. We create strain-induced pseudomagnetic fields and resulting flat electronic bands by tearing and folding graphene monolayer at arbitrary step edges. The intensity of the pseudomagnetic field can be readily tuned by changing the width of the folding edge, leading to the adjustability of the geometry of flat bands in folded graphene. By creating dispersionless flat bands using this technique, we successfully observe the correlation-induced splits of flat bands in the density of states.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Bo Li, Jing Wang, Qilong Wu, Qiwei Tian, Ping Li, Li Zhang, Long-Jing Yin, Yuan Tian, Ping Kwan Johnny Wong, Zhihui Qin, Lijie Zhang
Summary: In this study, a two-step method based on molecular beam epitaxy was used to successfully fabricate a PbSe-CuSe lateral heterostructure on the Cu(111) substrate. The heterostructure exhibits an atomically sharp interface. Scanning tunneling microscopy and spectroscopy measurements reveal the lattice characteristics and band gap of the structure, which are highly comparable to theoretical values. Density functional theory and crystal orbital Hamilton population analysis further confirm the weak interaction between the monolayer and the substrate. This work is of significance for further exploration of topology-derived quantum physics and phenomena in the monolayer limit.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Applied
Qilong Wu, Meysam Bagheri Tagani, Qiwei Tian, Sahar Izadi Vishkayi, Li Zhang, Long-Jing Yin, Yuan Tian, Lijie Zhang, Zhihui Qin
Summary: Researchers have successfully synthesized quasi-freestanding germanene with linear dispersion band structure on a WSe2/Au(100) substrate. They found that the interaction between germanene and the substrate destroys the sublattice symmetry and affects its electronic properties. Upon annealing in ultra-high vacuum, a bandgap opening of about 0.17 eV was observed in germanene, providing an effective method to tune its electronic properties.
APPLIED PHYSICS LETTERS
(2022)
Article
Physics, Applied
Qiwei Tian, Ping Li, Li Zhang, Yuan Tian, Long-Jing Yin, Lijie Zhang, Zhihui Qin
Summary: This study investigates the defect-induced p-type characteristics of epitaxial monolayer PbSe on Au(111) through scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The results demonstrate that Pb vacancies in the PbSe monolayer move the Fermi energy inside the valence band and produce extra holes, leading to p-type characteristics. This research provides valuable information for future research on device performance based on PbSe films.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Qiwei Tian, Sahar Izadi Vishkayi, Meysam Bagheri Tagani, Li Zhang, Yuan Tian, Long-Jing Yin, Lijie Zhang, Zhihui Qin
Summary: Researchers have successfully constructed two types of artificial germanium superlattices and confined the position of germanium atoms using a bismuth-induced electronic kagome lattice. The results show that at low temperature, germanium atoms form a single-atom superlattice, while at room temperature, germanium atoms and clusters are confined in different positions of the kagome lattice potential valleys, forming an artificial honeycomb superlattice.
Article
Chemistry, Multidisciplinary
Xiang Gong, Yueying Zhou, Jiangnan Xia, Li Zhang, Lijie Zhang, Long-Jing Yin, Yuanyuan Hu, Zhihui Qin, Yuan Tian
Summary: Floating-gate memories based on 2D vdW heterostructures have high performance and atmosphere stability, with a large current ratio and good extinction ratio. The storage performance can be regulated by optimizing the thickness of the insulating h-BN layer. The enhanced non-volatile characteristics enable the exploration of integrated 2D memory and potential multifunctionality.
Article
Chemistry, Multidisciplinary
Xiang Gong, Yueying Zhou, Jiangnan Xia, Li Zhang, Lijie Zhang, Long-Jing Yin, Yuanyuan Hu, Zhihui Qin, Yuan Tian
Summary: This article demonstrates a high performance and atmosphere stable floating-gate 2D InSe/h-BN/GaSe memory, which can be regulated by optimizing the thickness of the insulating h-BN layer. It also achieves a simulation of biological synaptic behavior on the same prototype device. Rating: 8/10.
Article
Materials Science, Multidisciplinary
Long-Jing Yin, Yue-Ying Zhou, Ling-Hui Tong, Zhihui Qin, Lin He
Summary: Quasiparticle interference-induced spatial standing waves in local density of states, namely Friedel oscillations, are observed in rhombohedral trilayer graphene for the first time using scanning tunneling microscopy and spectroscopy. These standing-wave patterns can be generated not only by the scattering off usual potential barriers like defects and step edges, but also by ABC-ABA stacking domain walls. The decay rate of Friedel oscillations in rhombohedral trilayer graphene is consistent with that in bilayer graphene and slower than that in monolayer graphene, confirming previous theoretical predictions.
Article
Materials Science, Multidisciplinary
Long-Jing Yin, Ling-Hui Tong, Yue-Ying Zhou, Yang Zhang, Yuan Tian, Li Zhang, Lijie Zhang, Zhihui Qin
Summary: By studying the local electronic properties of magic-angle twisted bilayer graphene, we observe a breakdown of the flat bands at the sample terminated edge. We find that complete moiré spots are necessary for the generation of effective flat bands in twisted bilayer graphene.
Article
Materials Science, Multidisciplinary
Long-Jing Yin, Li-Zhen Yang, Li Zhang, Qilong Wu, Xiaoshuai Fu, Ling-Hui Tong, Guang Yang, Yuan Tian, Lijie Zhang, Zhihui Qin
Article
Materials Science, Multidisciplinary
Long-Jing Yin, Li-Juan Shi, Li-Zhen Yang, Ling-Hui Tong, Lin He
Article
Physics, Multidisciplinary
Qin Zhi-Hui
ACTA PHYSICA SINICA
(2017)
Article
Chemistry, Physical
Erhao Gao, Wenjing Feng, Qi Jin, Li Han, Yi He
Summary: The influence of K-doping on the reactive oxygen species and elementary reactions of HCHO catalytic oxidation was investigated using density functional theory (DFT). The introduction of K-doping changed the electronic structures of Ce and O, facilitating the adsorption and activation of HCHO and O2 molecules, enhancing lattice oxygen mobility, and reducing the energy barrier for HCHO oxidation. K-doping also promoted the formation of hydroxyl groups, facilitating HCHO adsorption and oxidation.
Article
Chemistry, Physical
Hao Fu, Zhangliang Xu
Summary: In this study, the adsorption mechanisms and detection performance of formaldehyde, ammonia, and sulfur dioxide on undoped and metal-doped ZnO surfaces were investigated using density functional theory. The results showed that formaldehyde and ammonia were physically adsorbed on the undoped ZnO surface, while sulfur dioxide was weakly chemisorbed. The adsorption energy was enhanced when ZnO was doped with metals. These findings provide theoretical guidance for the application of ZnO substrate materials in gas sensitivity research.
Article
Chemistry, Physical
Atsushi Nomura, Tohru Kurosawa, Migaku Oda, Satoshi Demura, Shogo Kuwahara, Sora Kobayashi, Hideaki Sakata
Summary: The study investigates the tunneling spectra of 1T-TiSe2 in the CDW state and the dip structure below the Fermi level, aiming to determine whether this dip is a CDW gap. The answer to this question is crucial for understanding the driving mechanism of CDW.
Article
Chemistry, Physical
A. S. Petrov, D. I. Rogilo, A. I. Vergules, V. G. Mansurov, D. V. Sheglov, A. V. Latyshev
Summary: This study investigates Si mass transport and morphological transformations on the Si(111) surface during (root 3 x root 3)-Sn reconstruction formation and Si homoepitaxy. The research shows that the formation of different Sn phases at different temperatures affects the Si island nucleation and monatomic step shift, which in turn impact the morphology of the Sn/Si(111) interface. Electromigration-induced drift of disordered Sn domains leads to enhanced noncompensated Si mass transport and surface roughening.
Article
Chemistry, Physical
D. V. Gruznev, L. V. Bondarenko, A. Y. Tupchaya, A. A. Yakovlev, A. N. Mihalyuk, A. V. Zotov, A. A. Saranin
Summary: Deposition of thallium (Tl) onto the Au/Si(111)5 x 2 reconstruction followed by annealing results in the formation of a surface structure with 4 x 2 periodicity. The immiscibility of Au and Tl leads to the migration of Tl atoms over the Si chains. Thallium donates electrons to the surface, converting the metallic surface into an insulating state and altering the inter-chain distance within the array of Au atomic wires.
Article
Chemistry, Physical
Simone Giusepponi, Francesco Buonocore, Barbara Ferrucci, Massimo Celino
Summary: Using ab-initio calculations, the interaction between lead adatom and both clean and doped iron (100) surfaces was investigated. It was found that the lead adatom prefers to adsorb in the hollow site, which is more stable compared to the top and bridge sites, and in this position, it is energetically favorable over the iron adatom. Moreover, lead adsorbed in the hollow site of the iron (100) surface doped with chromium was found to create a more stable system compared to nickel-doped surfaces with an iron adatom in the same position. The study also explored inter-layer distances, bonding mechanisms, magnetic behaviors, and charge density differences. The results provide insights into the role of doping in the interaction between lead adatom and iron surface, and have implications for the analysis of corrosion processes caused by liquid lead.
Article
Chemistry, Physical
Shuo Zhang, Jin-Ho Choi
Summary: The recent synthesis of two-dimensional layered WSi2N4 has attracted attention due to its potential applications. This study investigates the catalytic performance of WSi2N4 monolayers with nitrogen vacancies in the hydrogen evolution reaction using first-principles calculations. The results show that the defective WSi2N4 monolayers exhibit remarkably high catalytic activity comparable to platinum catalysts. Electronic structure calculations also reveal the emergence of spin-polarized states due to the introduction of nitrogen vacancies.
Article
Chemistry, Physical
Xiaoyan Yu, Xin Cao, Wei Kang, Shanhua Chen, Ao Jiang, Yuhao Luo, Wenwei Deng
Summary: First-principles calculations were used to investigate the electronic properties of a TiO2 heterostructure modified with Bi2Te3 co-catalyst. The study revealed that the Bi2Te3/TiO2 interface introduced optimal band offsets, effectively suppressing electron-hole recombination and enhancing the utilization efficiency of photo-generated carriers. Additionally, the Bi2Te3 co-catalyst introduced extra catalytic active sites, further boosting the photo-catalytic hydrogen evolution efficiency.
Article
Chemistry, Physical
Filippo Longo, Emanuel Billeter, Selim Kazaz, Alessia Cesarini, Marin Nikolic, Aarati Chacko, Patrik Schmutz, Zbynek Novotny, Andreas Borgschulte
Summary: Alkaline water electrolysis is a simple and efficient method for renewable hydrogen production, utilizing cheap and abundant transition metals. The catalytic properties of Ni materials are enhanced by the formation of oxidized compounds on the surface. The high electrocatalytic activity of Ni (oxy)-hydroxides is directly related to water intercalation in the passivation layer, supporting the hypothesis of a water mediated OH- diffusion mechanism. The self-organization of the surface structure during passivation layer formation enables high electrode performance.
Article
Chemistry, Physical
Mohan Kumar Kuntumalla, Miriam Fischer, Alon Hoffman
Summary: By investigating the bonding, retention, and thermal stability of nitrogen in H-Diamond (100), it was found that nitrogen can partially recover its bonding with carbon atoms after high-temperature annealing, indicating a high thermal stability of nitrogen in diamond.
Article
Chemistry, Physical
Dong Yue, Liangying Wen, Rong Chen, Jianxin Wang, Zhongqing Yang
Summary: The adsorption behavior of Cl2 molecules on the TiC surface and the formation and transfer of reaction products were studied using first-principles ab initio calculations. The results show that the Cl atoms bonded to the surface Ti atoms are more stable, and the TiCl3 intermediate is easier to form than the TiCl2 intermediate.
Article
Chemistry, Physical
Yatao Wang, Peng Zhang, Hongjuan Li, Qiuju Xu, Shujun Liu, Xiaopeng Liu, Xuehua Guo, Yitao Li, Jinzhang Liu, Sen Dong, Zhi Wei Seh, Qianfan Zhang
Summary: In this study, the adsorption performance of two types of metal-organic frameworks (MOFs) for thiophene and benzene was experimentally investigated. The results showed that IZE-1 exhibited high selectivity and superior adsorption capacity for thiophene, especially at low concentrations. First-principles calculations and molecular dynamics simulations provided insights into the mechanism of thiophene adsorption and the high selectivity observed. This research demonstrates the potential of MOFs for thiophene adsorption, particularly at high concentrations.
