Article
Chemistry, Multidisciplinary
Thi-Nga Do, Danhong Huang, Po-Hsin Shih, Hsin Lin, Godfrey Gumbs
Summary: This paper introduces a generalized quantum-kinetic model that is coupled self-consistently with Maxwell and Boltzmann transport equations to accurately describe ultra-fast dephasing and scattering dynamics of electrons in graphene. The study emphasizes the importance of utilizing input from first-principles band-structure computations. The tight-binding model is applied to calculate band structures and wave functions in graphene, providing insights into electron behavior beyond effective low-energy theory.
Article
Chemistry, Physical
Debaprem Bhattacharya, Debnarayan Jana
Summary: Low energy Dirac material of carbon other than graphene has attracted researchers for their unique properties. Based on first-principles calculation, a carbon polymorph with a predominant Dirac cone near the Fermi level in the two-dimensional domain is proposed. The stable pristine structure, called Worm-graphene, has a similar atomic density to graphene and exhibits anisotropic properties. The material shows strain resilient semimetallic behavior with a robust Dirac cone, and the rolled-up nanotubes can be either semimetallic or semiconducting depending on the rolling direction. Additionally, the free-standing Worm-graphene sheet has a significantly different optical response compared to graphene.
APPLIED SURFACE SCIENCE
(2022)
Article
Materials Science, Multidisciplinary
Samira Jalilvand, Hamze Mousavi, Mahdi Irani
Summary: The effect of hydrogenation on the density of states, band structure, Pauli magnetic susceptibility, and electronic heat capacity of F-graphene were investigated. It was found that hydrogenation leads to a metal-to-semiconductor transition in F-graphene due to changes in its density of states and band structure, resulting in the formation of a bandgap.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Aleksander Bach Lorentzen, Mehdi Bouatou, Cyril Chacon, Yannick J. Dappe, Jerome Lagoute, Mads Brandbyge
Summary: Recent studies have shown the spatial control of nitrogen dopant concentration in graphene using a molecular mask. This technique enables the creation of ballistic electron optics-like structures and has implications for current focusing and quantized conductance.
Article
Materials Science, Multidisciplinary
Niklas Hofmann, Leonard Weigl, Johannes Gradl, Neeraj Mishra, Giorgio Orlandini, Stiven Forti, Camilla Coletti, Simone Latini, Lede Xian, Angel Rubio, Dilan Perez Paredes, Raul Perea Causin, Samuel Brem, Ermin Malic, Isabella Gierz
Summary: Ultrafast charge separation after photoexcitation is a common phenomenon in various van-der-Waals heterostructures with great relevance for future applications in light harvesting and detection. Theoretical understanding of this phenomenon converges towards a coherent mechanism through charge transfer states accompanied by energy dissipation into strongly coupled phonons. The detailed microscopic pathways are material specific as they sensitively depend on the band structures of the individual layers, the relative band alignment in the heterostructure, the twist angle between the layers, and interlayer interactions resulting in hybridization.
Article
Chemistry, Multidisciplinary
Vladimir V. Shnitov, Maxim K. Rabchinskii, Maria Brzhezinskaya, Dina Yu Stolyarova, Sergey Pavlov, Marina Baidakova, Aleksandr Shvidchenko, Vitaliy A. Kislenko, Sergey A. Kislenko, Pavel N. Brunkov
Summary: This study examines the engineering of 2D materials' electronic structure, focusing on how the introduction of functional groups affects the valence band. Core-level spectroscopy methods and density functional theory modeling are used to reveal the modification of graphene's valence band upon derivatization, with a proposed empirical approach to analyze and predict these effects. The results provide insight into band structure engineering of graphene derivatives and the mechanisms underlying the alteration of 2D materials' valence band structure upon derivatization.
Article
Physics, Condensed Matter
Eugene Kogan, Vyacheslav M. Silkin
Summary: The paper presents the symmetry labeling of all electron bands in graphene obtained by combining numerical band calculations and analytical analysis based on group theory. The predictions about relative positions of the bands which can be made on the basis of each of the models just using the group theory are complimentary.
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Hamze Mousavi, Samira Jalilvand, Sara Paikar
Summary: This study investigates the electronic properties of few-layer T-graphene nanoribbons (TGNRs) using the tight-binding model and Green's function formalism, comparing the results with monolayers. It is found that single-layer TGNRs with metallic properties retain this characteristic as the number of layers increases. Monolayers of aTGNR exhibit metallic and semiconducting properties depending on the width, while few-layer aTGNRs display both metallic and semiconducting characteristics based on layer stacking. Additionally, symmetric aTGNRs and metallic few-layer asymmetric aTGNRs have band structures with increasing Dirac points as their width and layers increase.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Chemistry, Multidisciplinary
Mattia Trama, Vittorio Cataudella, Carmine Antonio Perroni, Francesco Romeo, Roberta Citro
Summary: The electronic structure of the (111) LaAlO3/SrTiO3 interface was calculated using a tight binding supercell approach. The confinement potential at the interface was evaluated through the iterative solution of a discrete Poisson equation. Local Hubbard electron-electron terms were included at the mean-field level within a fully self-consistent procedure. The calculation accurately described the formation of a two-dimensional electron gas near the interface due to quantum confinement and showed agreement with experimental results.
Article
Multidisciplinary Sciences
Yali Zeng, Qilin Duan, Jinying Xu, Zhilin Yang, Huanyang Chen, Yineng Liu
Summary: This study proposes a single-layer twisted graphene-patterned metasurface with tilted elliptical hole arrays and theoretically reveals its tunable circular conversion dichroism (CCD) in the terahertz (THz) region. The unit cell of the metasurface is achiral, and by changing the in-plane orientation of holes for structural 2D chirality, a tunable CCD can be achieved at normal incidence. The reflection phase can be considered as an intuitive method to show the metasurface's anisotropy, and active CCD can be achieved based on the tunability of graphene.
Article
Chemistry, Physical
Xueyao Hou, Mansuer Wumiti, Shiv Kumar, Kenya Shimada, Masahiro Sawada
Summary: In this study, the electronic structure of the Cr2O3/graphene interface was investigated using first-principles calculations and experimental techniques. It was found that the mid-gap states are sensitive to the adsorption type of graphene and can be switched by changing the substrate magnetization direction.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
Qiang Sun, Hao Jiang, Yuyi Yan, Roman Fasel, Pascal Ruffieux
Summary: Graphene nanoribbons (GNRs) have unique electronic properties and can be synthesized with atomic precision via on-surface synthesis. In this study, pyrene-based GNRs were longitudinally fused on Au (111) through a surface assisted reaction, forming a molecular junction structure. The electronic properties of the structure were investigated using scanning tunneling spectroscopy (STS) and tight binding (TB) calculations.
Article
Chemistry, Multidisciplinary
Maxim K. Rabchinskii, Vladimir V. Shnitov, Maria Brzhezinskaya, Marina V. Baidakova, Dina Yu. Stolyarova, Sergey A. Ryzhkov, Svyatoslav D. Saveliev, Alexander V. Shvidchenko, Denis Yu. Nefedov, Anastasiia O. Antonenko, Sergey V. Pavlov, Vitaliy A. Kislenko, Sergey A. Kislenko, Pavel N. Brunkov
Summary: The derivatization of graphene has attracted significant attention for its potential applications in catalysis, sensing, and energy harvesting by engineering its band structure. The identification of specific functional groups and their effects on graphene's electronic structure remains a complex question. In this study, an advanced fingerprinting technique using core-level methods was proposed to accurately identify and quantify the epoxide and hydroxyl groups on the graphene layers. Experimental and theoretical results revealed the modification of graphene's valence band and the appearance of localized states related to the introduced functionalities. These findings advance the understanding of the contribution of epoxide and hydroxyl groups to the core-level spectra and band structure of graphene derivatives, enabling the engineering of graphene's physical properties through functionalization.
Article
Education, Scientific Disciplines
Mario Perez, Janet Elias, Modesto Sosa, Miguel Vallejo
Summary: This article reviews the basic theoretical aspects of graphene and presents a simplified and understandable approach to its structure and band properties. It aims to show that the abstract nature of graphene is not as daunting as it may seem.
EUROPEAN JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Zhehao Ge, Sergey Slizovskiy, Frederic Joucken, Eberth A. Quezada, Takashi Taniguchi, Kenji Watanabe, Vladimir Fal'ko, Jairo Velasco
Summary: Trilayer graphene with Bernal stacking is found to have topological magnetic moments with a large and widely tunable valley g factor, which can be utilized for creating valleytronic devices. The experimental results match well with the theoretical modeling, demonstrating the potential of controlling TLG bands under perpendicular electric and magnetic fields.
PHYSICAL REVIEW LETTERS
(2021)
