Article
Multidisciplinary Sciences
Dacen Waters, Ellis Thompson, Esmeralda Arreguin-Martinez, Manato Fujimoto, Yafei Ren, Kenji Watanabe, Takashi Taniguchi, Ting Cao, Di Xiao, Matthew Yankowitz
Summary: Moire patterns formed by stacking twisted atomically thin van der Waals crystals can modify the electronic properties of bulk graphitic thin films in a dual-gated device. At zero and small magnetic fields, transport is mediated by gate-tuneable moire and graphite surface states, as well as coexisting semimetallic bulk states. At high field, the moire potential hybridizes with the graphitic bulk states, creating a single quasi-two-dimensional hybrid structure. This study establishes twisted graphene-graphite as a new class of mixed-dimensional moire materials.
Article
Chemistry, Physical
Alexey Yu. Aladyshkin
Summary: In this study, the local structural and electronic properties of thin Pb(111) films grown on a Si(111)7 x 7 surface were investigated using low-temperature scanning tunneling microscopy and spectroscopy (STM/STS). It was found that the visible height of the monatomic step on the Pb(111) surface exhibited oscillatory dependence on a bias voltage. These oscillations coincided with the oscillations of both local tunneling conductance and the rate of the STM tip displacement at sweeping bias voltage, suggesting that they were controlled by coherent resonant tunneling of electrons from the STM tip to the thin Pb(111) film through quantum-well states. The maximum and minimum visible heights of the monatomic Pb(111) step were proposed to correspond to the bias voltages at which the local densities of states for Pb(111) terraces of different thicknesses were equal.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Materials Science, Multidisciplinary
Peter Thalmeier, Alireza Akbari
Summary: The passage discusses the protected helical surface states in thin films of topological insulators and the appearance of one-dimensional bound states and Majorana zero modes when a step is introduced in the film.
Article
Chemistry, Multidisciplinary
Sani van der Kley, Gabriele Goet, Anna Schmidt, Valentina Einspieler, Steven Wagner
Summary: This study identified wavelengths for measuring film thickness, urea concentration, and fluid temperature simultaneously. A high temporal resolution and non-intrusive measurement method was proposed to accurately capture the dynamic changes of film parameters.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Multidisciplinary
Jyrki Lappalainen, Matti Kangaspuoskari
Summary: The metal-insulator transition (MIT) of VO2 has attracted significant attention for its potential applications in nanostructured devices. The dynamics of the MIT phase transition play a crucial role in determining the feasibility of VO2 material properties in various applications. A new model is proposed to accurately predict the MIT effect in VO2 thin films by considering the interface structure and strain energy.
Article
Chemistry, Multidisciplinary
Anchal Rana, Aditya Yadav, Govind Gupta, Abhimanyu Rana
Summary: We present an efficient method of growing infrared (IR) sensitive mixed phase of V7O16 and V2O5 thin films at low temperatures. The mixed phase can be stabilized by annealing amorphous VxOy at 300-400 degrees C, and is fully converted into V2O5 after annealing at 450 degrees C. The optical transmission of the films increases with the content of V2O5, while the electrical conductivity and optical bandgap decrease. The IR sensitivity is explained by plasmonic absorption by the V7O16 degenerate semiconductor.
Article
Multidisciplinary Sciences
Ziming Shao, Noah Schnitzer, Jacob Ruf, Oleg Yu. Gorobtsov, Cheng Dai, Berit H. Goodge, Tiannan Yang, Hari Nair, Vlad A. Stoica, John W. Freeland, Jacob P. Ruff, Long- Qing Chen, Darrell G. Schlom, Kyle M. Shen, Lena F. Kourkoutis, Andrej Singer
Summary: New properties and exotic quantum phenomena can arise from periodic nanotextures, but visualizing nanoscale strain-modulated structural motifs remains challenging despite available tools to characterize atomic crystal structures.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Physics, Multidisciplinary
Hongyuan Li, Shaowei Li, Mit H. Naik, Jingxu Xie, Xinyu Li, Emma Regan, Danqing Wang, Wenyu Zhao, Kentaro Yumigeta, Mark Blei, Takashi Taniguchi, Kenji Watanabe, Sefaattin Tongay, Alex Zettl, Steven G. Louie, Michael F. Crommie, Feng Wang
Summary: Transition metal dichalcogenide moire heterostructures provide an ideal platform for studying the extended Hubbard model, where long-range Coulomb interactions are crucial. A scanning tunnelling microscopy technique is described for sensing and manipulating correlated electrons in gated WS2/WSe2 moire superlattice, allowing experimental extraction of fundamental extended Hubbard model parameters. This technique enables imaging and manipulation of the charge state of correlated electrons at local moire sites.
Article
Materials Science, Multidisciplinary
Juan Jiang, Alex Taekyung Lee, Sangjae Lee, Claudia Lau, Min Li, Tor M. Pedersen, Chong Liu, Sergey Gorovikov, Sergey Zhdanovich, Andrea Damascelli, Ke Zou, Frederick J. Walker, Sohrab Ismail-Beigi, Charles H. Ahn
Summary: This study investigates the synthesis and electronic properties of epitaxial perovskite La1-xSrxRhO3 thin films, revealing the effect of Sr doping on the electronic phase diagram. Experimental data show an insulator-metal-insulator transition caused by Sr addition, which is explained by theoretical calculations.
Article
Physics, Multidisciplinary
Ron Aharon Melcer, Sofia Konyzheva, Moty Heiblum, Vladimir Umansky
Summary: Thermal conductance measurements are crucial in condensed-matter physics for understanding topological order in two-dimensional topological insulators. A new local power measurement technique is presented to reveal the topological thermal Hall conductance, going beyond traditional two-terminal conductance measurements. This technique also proves useful in studying power carried by current fluctuations of partitioned edge modes with out-of-equilibrium distributions.
Article
Chemistry, Physical
Hyuk Jin Kim, Young Hwan Choi, Dongkyu Lee, In Hak Lee, Byoung Ki Choi, Soo-Hyon Phark, Young Jun Chang
Summary: Thermal stealth and camouflage have been extensively studied in order to blend objects with their surroundings against remote thermal image detection; Passive modulation of emissivity remains a great challenge requiring precise engineering over wide temperature range; The use of a vanadium dioxide layer with gradient tungsten concentration allows for self-adaptive thermal stealth without feedback control, improving passive camouflage materials.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Applied
Guowei Li, Jue Huang, Qun Yang, Liguo Zhang, Qingge Mu, Yan Sun, Stuart Parkin, Kai Chang, Claudia Felser
Summary: 2H-MoS2 is a promising non-noble metal electrocatalyst, but its performance is limited by the chemically inert basal plane; coupling with Bi2Te3 topological insulator films can enhance HER activities; theoretical investigations suggest that the charge redistribution at the interface and activation of topological surface states play a key role in enhancing catalytic activity.
JOURNAL OF ENERGY CHEMISTRY
(2021)
Article
Engineering, Electrical & Electronic
Yorick A. Birkholzer, Kai Sotthewes, Nicolas Gauquelin, Lars Riekehr, Daen Jannis, Emma van der Minne, Yibin Bu, Johan Verbeeck, Harold J. W. Zandvliet, Gertjan Koster, Guus Rijnders
Summary: Vanadium dioxide (VO2) is a promising material for electronic and optical switching due to its semiconductor-metal transition. In this study, we demonstrate the reversible manipulation and monitoring of VO2's semiconductor-to-metal transition using a nanosized metallic probe. The direct tunneling mechanism through the VO2-metal contact is observed, and the necessary pressure for the transition decreases with temperature. Our findings also provide valuable insights into oxide electronics for future design.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Chemistry, Physical
Shenli Zhang, I-Ting Chiu, Min-Han Lee, Brandon Gunn, Mingzhen Feng, Tae Joon Park, Padraic Shafer, Alpha T. N'Diaye, Fanny Rodolakis, Shriram Ramanathan, Alex Frano, Ivan K. Schuller, Yayoi Takamura, Giulia Galli
Summary: The oxygen vacancy concentration in cobaltites can be determined by the change in O K-edge XA spectra peak positions. The variation of Co-O bond length and Co-O-Co bond angle is also correlated with the presence of oxygen vacancies. The resistivity of the oxide material can be modified by adjusting the defect concentration, without any structural transformation.
CHEMISTRY OF MATERIALS
(2022)
Article
Physics, Applied
C. Barone, P. Orgiani, G. Carapella, V. Granata, S. K. Chaluvadi, S. Pagano
Summary: Topological insulators like Bi2Se3 have unique properties due to their distinct surface band structure. A study on low-frequency noise spectroscopy in Bi2Se3 thin films reveals a reduction in the 1/f noise component, especially at low temperatures. The correlation between this behavior and structural and dc electric transport investigations suggests the possibility of the occurrence of the topological regime. Flicker noise measurements could provide an alternative technique for studying topological surface states.
APPLIED PHYSICS LETTERS
(2023)
Review
Energy & Fuels
Bruno Schuler, Yunlong Zhang, Fang Liu, Andrew E. Pomerantz, A. Ballard Andrews, Leo Gross, Vincent Pauchard, Sanjoy Banerjee, Oliver C. Mullins
Article
Chemistry, Multidisciplinary
Lorel M. Scriven, Katharina Kaiser, Fabian Schulz, Alistair J. Sterling, Steffen L. Woltering, Przemyslaw Gawel, Kirsten E. Christensen, Harry L. Anderson, Leo Gross
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2020)
Article
Chemistry, Multidisciplinary
Florian Albrecht, Dulce Rey, Shadi Fatayer, Fabian Schulz, Dolores Perez, Diego Pena, Leo Gross
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Energy & Fuels
Pengcheng Chen, Shadi Fatayer, Bruno Schuler, Jordan N. Metz, Leo Gross, Nan Yao, Yunlong Zhang
Summary: The study focused on the reactions of 2,7-dimethylpyrene (DMPY) to understand the role of methyl substituents in reducing the thermal severity required for chemical reactions. Various analytical techniques were used to characterize the complex mixture of thermal products, including monomers, dimers, and trimers. The research also identified a wide range of structural transformations, such as methyl transfer and polymerization reactions, and gained a detailed understanding of the role of H radicals during the polymerization of polycyclic aromatic hydrocarbons.
Article
Physics, Multidisciplinary
Shadi Fatayer, Florian Albrecht, Ivano Tavernelli, Mats Persson, Nikolaj Moll, Leo Gross
Summary: By using single charge injections with an atomic force microscope, redox reactions of a molecule on a multilayer insulating film were investigated. Three channels for neutralization were observed and corresponding to transitions to different excited states. Energy differences between these transitions were measured using single-electron tunneling spectroscopy, and compared with density functional theory calculations. The results show that excited states of molecules can be prepared and their optical gap energies can be quantified through controlled single-charge injections.
PHYSICAL REVIEW LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Jacob W. Martin, Laura Pascazio, Angiras Menon, Jethro Akroyd, Katharina Kaiser, Fabian Schulz, Mario Commodo, Andrea D'Anna, Leo Gross, Markus Kraft
Summary: Evidence of a reactive pi-diradical aromatic soot precursor imaged using non-contact atomic force microscopy has been shown, which can undergo barrierless chain reactions to form thermally stable aromatic rim-linked hydrocarbons under flame conditions. Quantum molecular dynamics simulations demonstrate physical condensation of aromatics that survive for tens of picoseconds, providing a rapid, thermally stable chain reaction toward soot nanoparticle formation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Multidisciplinary Sciences
Jinbo Peng, Sophia Sokolov, Daniel Hernangomez-Perez, Ferdinand Evers, Leo Gross, John M. Lupton, Jascha Repp
Summary: In this study, the triplet lifetime of molecules was directly measured using single-molecule manipulation techniques with atomic resolution, revealing strong quenching effects when oxygen molecules are coadsorbed closely. The electrical addressing of long-lived triplets of single molecules, combined with atomic-scale manipulation, provides new routes to control and study local spin-spin interactions.
Article
Chemistry, Multidisciplinary
Shantanu Mishra, Shadi Fatayer, Saleta Fernandez, Katharina Kaiser, Diego Pena, Leo Gross
Summary: We report the on-surface synthesis of a non-benzenoid triradical through dehydrogenation of truxene (C27H18) on coinage metal and insulator surfaces. The final product truxene-5,10,15-triyl (1) retains its open-shell quartet ground state on a two monolayer-thick NaCl layer on a Cu(111) surface, and its frontier orbital densities correspond to spin-split singly occupied molecular orbitals.
Article
Chemistry, Multidisciplinary
Jesus Castro-Esteban, Florian Albrecht, Shadi Fatayer, Dolores Perez, Leo Gross, Diego Pena
Summary: The study successfully demonstrated an on-surface hexadehydro-Diels-Alder reaction at the single-molecule level using atomic force microscopy. This finding opens up new possibilities for introducing the concept of atom economy in the field of on-surface synthesis.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Geochemistry & Geophysics
Katharina Kaiser, Fabian Schulz, Julien F. Maillard, Felix Hermann, Iago Pozo, Diego Pena, H. James Cleaves, Aaron S. Burton, Gregoire Danger, Carlos Afonso, Scott Sandford, Leo Gross
Summary: Researchers used high-resolution atomic force microscopy to atomically resolve individual molecules from Murchison meteorite samples. They also proposed a method for extracting and preparing meteorite samples for investigation. By processing the samples, they were able to increase the fraction of molecules that could be resolved by atomic force microscopy and identify organic constituents and molecular moieties.
METEORITICS & PLANETARY SCIENCE
(2022)
Article
Multidisciplinary Sciences
Florian Albrecht, Shadi Fatayer, Iago Pozo, Ivano Tavernelli, Jascha Repp, Diego Pena, Leo Gross
Summary: This work demonstrates reversible and selective bond formation and dissociation promoted by tip-induced reduction-oxidation reactions on a surface. Molecular rearrangements leading to different constitutional isomers are selected by the polarity and magnitude of applied voltage pulses from the tip. Density functional theory calculations reveal the importance of the energy landscape of the isomers in different charge states for rationalizing the selectivity.
Correction
Multidisciplinary Sciences
Katharina Kaiser, Leonard-Alexander Lieske, Jascha Repp, Leo Gross
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Katharina Kaiser, Leonard-Alexander Lieske, Jascha Repp, Leo Gross
Summary: In this study, the authors investigated the charge-state lifetimes of single molecules through NaCl films and revealed the critical role of the substrate's level alignment with the insulator and metal-insulator interface state.
NATURE COMMUNICATIONS
(2023)
Article
Astronomy & Astrophysics
Fabian Schulz, Julien Maillard, Katharina Kaiser, Isabelle Schmitz-Afonso, Thomas Gautier, Carlos Afonso, Nathalie Carrasco, Leo Gross
Summary: The atmosphere of Titan is filled with a thick organic photochemical haze composed of nitrogenated-polycyclic aromatic hydrocarbons (N-PAH). Researchers simulated the synthesis of this haze in the laboratory, extracting small N-PAH molecules to understand the formation process. Key chemical structures were imaged using high-resolution atomic force microscopy, bridging the gap between gas phase atmospheric reactants and the macroscopic structure of Titan's haze.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Multidisciplinary Sciences
Shadi Fatayer, Florian Albrecht, Yunlong Zhang, Darius Urbonas, Diego Pena, Nikolaj Moll, Leo Gross
