Article
Chemistry, Multidisciplinary
Alessandra Canetta, Sergio Gonzalez-Munoz, Viet-Hung Nguyen, Khushboo Agarwal, Pauline de Crombrugghe de Picquendaele, Yuanzhuo Hong, Sambit Mohapatra, Kenji Watanabe, Takashi Taniguchi, Bernard Nysten, Benoit Hackens, Rebeca Ribeiro-Palau, Jean-Christophe Charlier, Oleg Victor Kolosov, Jean Spiece, Pascal Gehring
Summary: Using Ultrasonic Force Microscopy (UFM), researchers have quantified the variation of out-of-plane Young's modulus in minimally twisted double bilayer graphene (TDBG). They found a softening of the Young's modulus by 7% and 17% along single and double domain walls, respectively. This study highlights the tunability of nanomechanical properties in engineered twisted materials and opens new possibilities for future applications of designer 2D nanomechanical systems.
Article
Nanoscience & Nanotechnology
Jiaying Shen, Zhengang Dong, MingQun Qi, Yang Zhang, Chao Zhu, Zhenping Wu, Danfeng Li
Summary: This study reveals a method for constructing artificial oxide heterostructures based on high-quality nanomembrane structures, and provides a material foundation for investigating moire-related electronic effects in twisted oxide thin films.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Multidisciplinary
Junxi Duan, Yu Jian, Yang Gao, Huimin Peng, Jinrui Zhong, Qi Feng, Jinhai Mao, Yugui Yao
Summary: In the study, a giant second-order nonlinear Hall effect dominated by disorder-induced skew scattering was observed in twisted bilayer graphene. The magnitude and direction of the nonlinearity could be effectively tuned by gate voltage, and was mainly determined by the collaboration of static and dynamic disorders.
PHYSICAL REVIEW LETTERS
(2022)
Article
Chemistry, Physical
Nathanael P. Kazmierczak, Madeline Van Winkle, Colin Ophus, Karen C. Bustillo, Stephen Carr, Hamish G. Brown, Jim Ciston, Takashi Taniguchi, Kenji Watanabe, D. Kwabena Bediako
Summary: Twisted bilayer graphene exhibits two-regime reconstruction mechanics based on twist angle, with applied heterostrain accumulating anisotropically in saddle-point regions to generate distinctive striped strain phases. Nanoscale spatial fluctuations in twist angle and uniaxial heterostrain were statistically evaluated, revealing the prevalence of short-range disorder in moire heterostructures. This study provides insights into the twist-angle-dependent electronic behavior and structural relaxation, disorder, and strain in moire materials.
Article
Multidisciplinary Sciences
Yuan Hou, Zhaohe Dai, Shuai Zhang, Shizhe Feng, Guorui Wang, Luqi Liu, Zhiping Xu, Qunyang Li, Zhong Zhang
Summary: This study demonstrates that nanopockets in vdW materials can coalesce spontaneously into larger spaces which can be easily cleaned through mechanical methods, and that bilayer graphene interfaces exhibit excellent self-renewal phenomena in terms of moire patterns recovery after motion of contaminants.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Yanbang Chu, Le Liu, Cheng Shen, Jinpeng Tian, Jian Tang, Yanchong Zhao, Jieying Liu, Yalong Yuan, Yiru Ji, Rong Yang, Kenji Watanabe, Takashi Taniguchi, Dongxia Shi, Fengcheng Wu, Wei Yang, Guangyu Zhang
Summary: In this study, experiments were conducted to investigate the temperature-linear resistivity in twisted double-bilayer graphene (TDBG) under different conditions, showing diverse behaviors such as T-linear, slope decreasing with carrier density, and maximum slope at the emergence of correlated states.
Article
Chemistry, Multidisciplinary
Xiaoqian Liu, Ran Peng, Zhaoru Sun, Jianpeng Liu
Summary: In this study, the phonon properties of magic-angle twisted bilayer graphene (TBG) were investigated using many-body classical potential and interatomic forces generated by a deep neural network. Various vibrational patterns and their effects on electronic structures were discovered.
Article
Chemistry, Multidisciplinary
Nicholas Dale, M. Iqbal Bakti Utama, Dongkyu Lee, Nicolas Leconte, Sihan Zhao, Kyunghoon Lee, Takashi Taniguchi, Kenji Watanabe, Chris Jozwiak, Aaron Bostwick, Eli Rotenberg, Roland J. Koch, Jeil Jung, Feng Wang, Alessandra Lanzara
Summary: Using ARPES, the effects of many-body interactions and displacement field on the band structure of twisted bilayer graphene (tBG) devices at an intermediate (3 degrees) twist angle are studied. The observed renormalization of bands at the K points suggests the influence of moire models of the Hartree-Fock interaction. Evidence of correlation-enhanced inversion symmetry-breaking, shown as tunable gaps at the Dirac points, suggests a new approach to engineering band structure and symmetry-breaking phases in moire heterostructures.
Article
Materials Science, Multidisciplinary
Tawfiqur Rakib, Elif Ertekin, Pascal Pochet, Harley T. Johnson
Summary: In low-angle twisted bilayer graphene, electronic properties are influenced by the atomic structure; relaxation causes changes in symmetry; a computationally efficient framework has been developed to explore charge density symmetry.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
A. S. Shankar, D. O. Oriekhov, Andrew K. Mitchell, L. Fritz
Summary: The emergence of flat bands in twisted bilayer graphene at the magic angle can be understood as a result of vanishing Fermi velocity of the Dirac cone and higher-order van Hove singularities. These characteristics play an important role in exotic phenomena observed in this material, such as superconductivity and magnetism, by enhancing electronic correlation effects. One of these correlation effects is the Kondo effect due to a magnetic impurity embedded in twisted bilayer graphene. The interplay between Dirac, van Hove, and Kondo physics leads to nontrivial behavior at finite temperatures relevant to experiments.
Article
Chemistry, Multidisciplinary
Fang Yuan, Yanyu Jia, Guangming Cheng, Ratnadwip Singha, Shiming Lei, Nan Yao, Sanfeng Wu, Leslie M. Schoop
Summary: We develop a robust method for atomic-resolution visualization of monolayers and twisted-bilayer WTe2 (tWTe(2)), confirming their high crystalline quality and structural stability. Our findings provide important experimental information for modeling the physical properties of 2D WTe2 systems.
Article
Physics, Multidisciplinary
Pawel Potasz, Ming Xie, A. H. MacDonald
Summary: This study reports on finite-size exact-diagonalization calculations in a Hilbert space defined by the continuum-model flat moire bands of magic angle twisted bilayer graphene, showing evidence of a spin ferromagnet ground state for moire band filling between 3 and 2, and Chern insulator ground states with spontaneous spin, valley, and sublattice polarization near filling 3. It is emphasized that the inclusion of remote band self-energy is crucial for a reliable description of flat band correlations in magic angle twisted bilayer graphene.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Dumitru Calugaru, Nicolas Regnault, Myungchul Oh, Kevin P. Nuckolls, Dillon Wong, Ryan L. Lee, Ali Yazdani, Oskar Vafek, B. Andrei Bernevig
Summary: This article analytically computes the scanning tunneling microscopy (STM) signatures of integer-filled correlated ground states of the magic angle twisted bilayer graphene (TBG) narrow bands and assesses the possibility of Kekule distortion (KD). The results show that coupling the two opposite graphene valleys does not always result in KD.
PHYSICAL REVIEW LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Ipsita Mandal, Jia Yao, Erich J. Mueller
Summary: Experiments have shown that insulating behavior emerges in graphene bilayers when the moire bands are partially filled and the top layer is rotated relative to the bottom layer. By calculating charge distributions and estimating excitation gaps, researchers are able to further understand the properties of these phases.
Article
Materials Science, Multidisciplinary
Zhen-Bing Dai, Zhiqiang Li, Yan He
Summary: The study investigates the optical response of bilayer graphene with a kink potential and finds that the one-dimensional chiral states localized at the domain wall significantly contribute to the local optical conductivity. The effects of domain wall states on optical conductivity can be detected through spatially and frequency-resolved spectroscopic features. The spatial distribution of local optical conductivity can provide important information on bound states and topological domain wall states when the domain wall region is broad.
Correction
Optics
Tatiana Latychevskaia
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2020)
Article
Microscopy
Tatiana Latychevskaia, Yichao Zou, Colin Robert Woods, Yi Bo Wang, Matthew Holwill, Eric Prestat, Sarah J. Haigh, Kostya S. Novoselov
Article
Optics
Tatiana Latychevskaia
Summary: The study introduces methods of three-dimensional deconvolution and demonstrates the effectiveness of recovering different types of samples through non-iterative and iterative algorithms. It is shown that only iterative algorithms combined with optimal protocols can accurately recover the 3D sample distribution.
Article
Chemistry, Physical
T. Latychevskaia, S. J. Haigh, K. S. Novoselov
Summary: Convergent beam electron diffraction (CBED) has been widely used in studying 2D materials to investigate structural defects, adsorbates, atomic displacements, and interlayer distances. The interference patterns in individual CBED spots of 2D crystals can be reconstructed using conventional holography methods. Recent studies have applied CBED to analyze defects, interlayer distances, adsorbates, and moire patterns in van der Waals systems.
SURFACE REVIEW AND LETTERS
(2021)
Correction
Optics
Tatiana Latychevskaia, Fabian Gehri, Hans-Werner Fink
Article
Physics, Multidisciplinary
Tatiana Latychevskaia
Summary: In this study, a new method is proposed to reconstruct 3D sample distribution from a single 2D intensity measurement, exceeding the classical limit in z resolution. This method is practical for radiation-sensitive materials or experimental setups with constraints on the number of intensity measurements.
PHYSICAL REVIEW LETTERS
(2021)
Article
Microscopy
Tatiana Latychevskaia, Recep Zan, Sergey Morozov, Kostya S. Novoselov
Summary: The study introduces a new theoretical approach beyond the weak phase approximation, allowing for the analysis of electron diffraction patterns in 2D crystals with different scattering characteristics. The symmetry of the exit wave unit cell distribution determines the symmetry of the diffraction pattern, with expectations of symmetrical patterns for identical atom arrangements and non-symmetrical patterns for TMD materials.
Article
Optics
Tatiana Latychevskaia
Summary: This study further investigates the methods of three-dimensional (3D) wavefront intensity modulation using contrast-inverted holography, with a focus on creating smooth appearance of 3D curves. It demonstrates the use of spherical waves for 3D wavefront modulation and discusses the miniaturization of 3D intensity beams, showing that the resolution and size of the created structures are determined by the wavelength of the employed radiation. The study also explores applications of the presented methods in various techniques such as lithography, micro-robotics, and particle trapping, indicating their broad utility across different types of waves.
Article
Microscopy
Tatiana Latychevskaia, Cathal Cassidy, Tsumoru Shintake
Summary: Crystal diffraction is a well-established technique for high-resolution structural analysis, but it can smear out imperfections and defects in the crystal. Bragg holography offers a way to image nano-crystals at a defocus distance, allowing separation of diffracted beams without turning them into peaks. This technique provides a complete complex-valued wavefront with information about atomic distribution, including defects, and has been successfully demonstrated for gold nano-crystals with feasibility shown for biological nano-crystals.
Article
Multidisciplinary Sciences
Tatiana Latychevskaia, Alice Kohli
Summary: A low-dose imaging technique is proposed, where recognition is used instead of recording high-resolution images to verify structural hypotheses. By detecting only a few scattered particles, a structural hypothesis can be confirmed with a probability exceeding 95%. This technique can be applied to optical character recognition and minimizing radiation damage in sensitive materials.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Physical
Tatiana Latychevskaia, Colin Robert Woods, Yi Bo Wang, Matthew Holwill, Eric Prestat, Sara Mustafi, Sarah J. Haigh, Konstantin S. Novoselov
Summary: This study demonstrates the possibility of directly measuring scattering parameters through the intensity distribution of spots in CBED patterns. A method for recovering atomic scattering parameters from CBED patterns is proposed and validated through experiments and simulations.
Review
Optics
Sara Mustafi, Tatiana Latychevskaia
Summary: Fourier transform holography (FTH) is a lensless imaging technique that reconstructs the distribution of an object by superimposing the waves scattered by the object and a reference source in the same plane. This study provides an overview of the basic principles, different types of references, and reconstruction algorithms of FTH. It also discusses the current applications of FTH with different waves (light, electron, and X-ray) and their relationships with other coherent imaging techniques.
Editorial Material
Nanoscience & Nanotechnology
Tatiana Latychevskaia
Summary: The topological parameters of the channel network in twisted bilayer graphene can be manipulated by intercalating lithium atoms.
NATURE NANOTECHNOLOGY
(2023)
Article
Microscopy
Tatiana Latychevskaia
Summary: This study provides theoretical considerations and models for the quantitative analysis of experimental data observed in low-energy electron transmission microscopy and in-line holography. The results show that the scattering and imaging parameters of low-energy electrons can be quantitatively described, and the blurring phenomenon in imaging of objects with finite thickness is explained. A simple method to quantitatively evaluate the absorption properties of a specimen from its in-line hologram is presented.
Article
Materials Science, Multidisciplinary
Tatiana Latychevskaia, Pengru Huang, Kostya S. Novoselov
Summary: In this study, we demonstrate how convergent-beam electron diffraction (CBED) can be used for atomic-precision imaging of individual defects in 2D materials. By combining structural calculations and density-functional theory, we present simulated CBED patterns and show how atomic positions can be reconstructed through iterative phase retrieval.
Article
Microscopy
C. Gao, C. Hofer, T. J. Pennycook
Summary: Ptychography provides high dose efficiency images that can reveal light elements next to heavy atoms. However, contrast reversals can occur when the projected potential becomes strong. Recent research has shown that these reversals can be counteracted by adapting the focus. This study explains why the best contrast is often found with the probe focused to the middle of the sample and highlights the importance of convergence angle in thin samples to remove contrast reversals.
Article
Microscopy
J. Lindner, U. Ross, T. Meyer, V. Boureau, M. Seibt, Ch. Jooss
Summary: Phase-shifting electron holography is an excellent method with high phase sensitivity to reveal electron wave phase information. An advanced drift correction scheme is proposed in this study, which exploits the interface of the TEM specimen and the vacuum area in the hologram. This method allows for obtaining reliable phase information.
Article
Microscopy
Ali Jaberi, Nicolas Brodusch, Jun Song, Raynald Gauvin
Summary: This study investigates knock-on damage in lithium-ion batteries (LIBs) by computing threshold displacement energies (TDEs) and performing Monte Carlo simulation. The results indicate that Li is most sensitive to knock-on damage at moderate electron energies, and TDE is the principal parameter for assessing Li sensitivity to knock-on damage across similar structures.
Article
Microscopy
Alexander Schroeder, Christopher Rathje, Leon van Velzen, Maurits Kelder, Sascha Schaefer
Summary: This study utilizes novel event-based electron detector platforms to extend the temporal resolution of electron microscopy. By training a neural network to predict electron arrival time, the researchers were able to improve the timing accuracy and achieve a promising solution for enhancing electron timing precision in various electron microscopy applications.
Article
Microscopy
Avi Auslender, Nivedita Pandey, Amit Kohn, Oswaldo Dieguez
Summary: This article describes a faster implementation based on DFT for computing the mean inner potential of crystals, providing quantum-mechanical calculations beyond the independent-atom approximation. The study also reveals the dependence of the mean inner potential on sample boundary conditions, mass density, and magnetic susceptibility, highlighting its correlation with various material properties.
Article
Microscopy
Zhidong Yang, Dawei Zang, Hongjia Li, Zhao Zhang, Fa Zhang, Renmin Han
Summary: In this work, we propose a self-supervised deep learning model for cryo-ET volumetric image denoising based on noise modeling and sparsity guidance. Experimental results demonstrate that our method can achieve reliable denoising by training on single noisy volume and outperform existing methods.
Article
Microscopy
J. Kuttruff, J. Holder, Y. Meng, P. Baum
Summary: In this study, a robust clustering algorithm is proposed that can find clusters in a continuous stream of raw data in real time. This algorithm converts pixel hits measured by hybrid pixel detectors to real single-electron events. By continuously comparing with previous hits, the algorithm efficiently identifies the merging of new and old events.
Article
Microscopy
D. G. Senturk, C. P. Yu, A. De Backer, S. Van Aert
Summary: This article presents a statistics-based method for accurately counting the number of atoms in nanostructures, especially for images acquired with low electron doses and multiple element structures.
Article
Microscopy
Mauricio J. Prieto, Lucas de Souza Caldas, Liviu C. Tanase, Thomas Schmidt, Oscar Rodriguez de la Fuente
Summary: This study presents a synchrotron-based investigation of the synthesis process of a magnetite/hematite bilayer. Ion bombardment gradually transforms hematite into magnetite, and the growth of magnetite leads to the formation of stable boundaries. These findings are significant for understanding novel oxide heterostructures.
Article
Microscopy
Emre Yoruk, Holger Klein, Stephanie Kodjikian
Summary: Beam sensitive nanomaterials pose challenges for crystallographic structure determination. A dose symmetric electron diffraction tomography (DS-EDT) method is developed to reduce beam damage and obtain complete data sets by merging individual datasets from multiple crystals.
Article
Microscopy
A. Pofelski, Y. Zhu, G. A. Botton
Summary: The precision and sensitivity of the GPA method for strain characterization is a widely discussed topic. This study introduces the concept of phase noise and analyzes the parameter of sampling to improve the precision of GPA. Experimental and theoretical results demonstrate that using a larger pixel spacing in STEM can enhance the precision and sensitivity of the GPA method.
Article
Microscopy
Sangjun Kang, Di Wang, Christian Kuebel, Xiaoke Mu
Summary: Transmission electron microscopy is a valuable tool for assessing strain fields within materials. However, using thin specimens in TEM analysis can affect atomic configuration and deformation structure.