Honeycomb Lattice Structure Research Articles

Research of Graphene Electronics and its Applications

Imagine a material as thin as a single atom, yet stronger than steel and more conductive than copper. This is graphene, a two-dimensional wonder material with a unique monolayer hexagonal honeycomb lattice structure. Its exceptional electrical properties, particularly its high carrier mobility, have sparked widespread interest in the scientific community for potential applications in electronics.However, because its conduction and valence bands intersect at the Dirac point, it behaves as a zero-bandgap semimetal, limiting its use in electronic devices. Therefore, opening a bandgap has become a focal research task in the scientific community. This paper explains the inherent conductivity of intrinsic graphene and summarizes how doping can theoretically further enhance its conductivity. Through further research on the development of graphene doping methods, this article primarily introduces how adsorption doping and lattice doping techniques can open the bandgap of graphene. It analyzes the stability of different doping types to achieve their application in nanoelectronic devices.

Nernst effect of the dice lattice in a strong magnetic field

The dice lattice bears a similar honeycomb lattice structure to graphene but with a non-dispersive flat band intersecting the Dirac bands at the band center. In this work, we investigate Nernst effect of the dice lattice in a strong magnetic field, focusing on the role of the flat band. By using the Chebyshev polynomial Green’s function method, we show that no Nernst effect (Sxy=0) is around the Dirac point in the clean limit contrary to the graphene case because of the existence of a zero Hall conductivity platform. However, an unconventional negative Sxy of the double-peak structure emerges instead when the flat band is broadened by disorder and temperature. In addition, when a mass term of Dirac electrons is introduced in the system to open an energy gap, a negative single peak of Sxy appears at the Dirac point and this is due to the derivative quantum Hall effect of non-Dirac electrons in the flat band appearing in the energy gap.

Real-Space Imaging of Intrinsic Symmetry-Breaking Spin Textures in a Kagome Lattice.

The electronic orders in kagome materials have emerged as a fertile platform for studying exotic quantum states, and their intertwining with the unique kagome lattice geometry remains elusive. While various unconventional charge orders with broken symmetry is observed, the influence of kagome symmetry on magnetic order has so far not been directly observed. Here, using a high-resolution magnetic force microscopy, it is, for the first time, observed a new lattice form of noncollinear spin textures in the kagome ferromagnet in zero magnetic field. Under the influence of the sixfold rotational symmetry of the kagome lattice, the spin textures are hexagonal in shape and can further form a honeycomb lattice structure. Subsequent thermal cycling measurements reveal that these spin textures transform into a non-uniform in-plane ferromagnetic ground state at low temperatures and can fully rebuild at elevated temperatures, showing a strong second-order phase transition feature. Moreover, some out-of-plane magnetic moments persist at low temperatures, supporting the Kane-Mele scenario in explaining the emergence of the Dirac gap. The observations establish that the electronic properties, including both charge and spin orders, are strongly coupled with the kagome lattices.

Mechanistic divergences of endocytic clathrin-coated vesicle formation in mammals, yeasts and plants.

Clathrin-coated vesicles (CCVs), generated by clathrin-mediated endocytosis (CME), are essential eukaryotic trafficking organelles that transport extracellular and plasma membrane-bound materials into the cell. In this Review, we explore mechanisms of CME in mammals, yeasts and plants, and highlight recent advances in the characterization of endocytosis in plants. Plants separated from mammals and yeast over 1.5 billion years ago, and plant cells have distinct biophysical parameters that can influence CME, such as extreme turgor pressure. Plants can therefore provide a wider perspective on fundamental processes in eukaryotic cells. We compare key mechanisms that drive CCV formation and explore what these mechanisms might reveal about the core principles of endocytosis across the tree of life. Fascinatingly, CME in plants appears to more closely resemble that in mammalian cells than that in yeasts, despite plants being evolutionarily further from mammals than yeast. Endocytic initiation appears to be highly conserved across these three systems, requiring similar protein domains and regulatory processes. Clathrin coat proteins and their honeycomb lattice structures are also highly conserved. However, major differences are found in membrane-bending mechanisms. Unlike in mammals or yeast, plant endocytosis occurs independently of actin, highlighting that mechanistic assumptions about CME across different systems should be made with caution.

The Growth Mechanism of Layered Hexagonal Boron Nitride Crystal on Copper Foil

Abstract2D hexagonal boron nitride (h‐BN), which has a similar honeycomb lattice structure to graphene, is a promising dielectric material for a wide variety of applications. Herein, the growth of high‐quality and large‐size multilayer h‐BN crystals on Cu foils is reported by chemical vapor deposition (CVD) at atmospheric pressure. The size of an individual isolated hexagonal crystal of h‐BN is about 20 µm, and the thickness is 3 nm. This paper studies the variables that affect h‐BN growth during the process and the microstructure changes during the growth. Through analysis of the thermal and dynamic processes of chemical vapor deposition, relationships are derived between the mass of h‐BN grown in the gas phase and various temperature and pressure factors. This information is used to develop appropriate parameters for commercial copper foil growth. Finally, using optimized conditions, high‐quality h‐BN at high pressure and low gas flow conditions are grown.

Mechanical Behavior Analysis of Double-Layer Graphene Based on Football and Meshless kp-Ritz Method

Graphene is a double-layer flat film composed of multiple atoms. It is mainly based on the hexagonal honeycomb lattice structure composed of carbon atoms in a hybrid structure. The three-dimensional image is like a grid shape on the surface of a football. Double-layer graphene is a two-carbon material composed of two layers of carbon atoms that are periodically and closely packed in a benzene ring structure stacked in a different stacking manner. In this article, this article aims to study the thermodynamic behavior analysis of double-layer graphene. According to a mechanical behavior analysis of football and meshless kp-Rit method, due to the thermodynamic instability of two-dimensional crystals, no matter what whether it is a football shape or a meshless method, the graphene is not a complete plane either freely or deposited on the substrate. On the contrary, there are microscopic wrinkles on the surface. According to observations, this three-dimensional change will cause the generation of static electricity. At the same time, it will also make the connection between different carbon atoms more viscous, and the properties will be more stable. Study the tensile force with stronger fracture strength than steel, through the study of meshless methods and mechanical research models Established, and finally showed that in the experimental results in this article, the angle between the bond and the bond is 120°, and its strength can reach about 150 GPa.

Nanoscale Evaluation of the Degradation Stability of Black Phosphorus Nanosheets Functionalized with PEG and Glutathione-Stabilized Doxorubicin Drug-Loaded Gold Nanoparticles in Real Functionalized System.

Two-dimensional black phosphorus (2D BP) has attracted significant research interest in the field of biomedical applications due to its unique characteristics, including high biocompatibility, impressive drug-loading efficiency, phototherapeutic ability, and minimal side effects. However, its puckered honeycomb lattice structure with lone-pair electrons of BP leads to higher sensitivity and chemical reactivity towards H2O and O2 molecules, resulting in the degradation of the structure with physical and chemical changes. In our study, we synthesize polyethylene glycol (PEG) and glutathione-stabilized doxorubicin drug-assembled Au nanoparticle (Au-GSH-DOX)-functionalized BP nanosheets (BP-PEG@Au-GSH-DOX) with improved degradation stability, biocompatibility, and tumor-targeting ability. Transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy indicate the nanoscale degradation behavior of synthesized nanoconjugates in three different environmental exposure conditions, and the results demonstrate the remarkable nanoscale stability of BP-PEG@Au-GSH-DOX against the degradation of BP, which provides significant interest in employing 2D BP-based nanotherapeutic agents for tumor-targeted cancer phototherapy.

Dual-band filtering and enhanced directional via tunable acoustic metamaterial antennas

The detection of acoustic signals in strong background noise plays a crucial role in industrial non-destructive, mechanical equipment health monitoring and acoustic communication. The major bottleneck of this technology lies in the limited high-sensitivity and high-directivity of acoustic sensors. Here, this study proposes a tunable acoustic metamaterial antenna (TAMAA) with a double bandgap and near-zero refractive index. Different from the traditional geometric scatterer, a gear-shaped structure is introduced to enhance the controllability of the acoustic system. We theoretically demonstrate the physical properties of the structure with a double bandgap and near-zero refractive index. Remarkably, the gear-shaped honeycomb lattice structure exhibits an adjustable bandgap region, which enables the multiplexing of both acoustic shielding and acoustic enhancement functions by controlling the rotation angle of the scatterer. Furthermore, through numerical computational and experimental studies, we demonstrate that the proposed TAMAA exhibits dual-band filtering capabilities and provides excellent acoustic directional enhancement. Moreover, it allows for the recovery of weak acoustic signals even in the presence of extremely low signal-to-noise ratio and strong spatial noise interference. This work breaks through the detection limits of conventional acoustic sensing systems and provides new ideas for the development of acoustic sensing detection.

Experimental and Numerical Investigation of Polymer-Based 3D-Printed Lattice Structures with Largely Tunable Mechanical Properties Based on Triply Periodic Minimal Surface.

Triply periodic minimal surfaces (TPMSs) have demonstrated significant potential in lattice structure design and have been successfully applied across multiple industrial fields. In this work, a novel lattice structure with tunable anisotropic properties is proposed based on two typical TPMS types, and their mechanical performances are studied both experimentally and numerically after being fabricated using a polymer 3D printing process. Initially, adjustments are made to the original TPMS lattice structures to obtain honeycomb lattice structures, which are found to possess significant anisotropy, by utilizing numerical homogenization methods. Based on this, a continuous self-twisting deformation is proposed to change the topology of the honeycomb lattice structures to largely tune the mechanical properties. Quasi-static compression experiments are conducted with different twisting angles, and the results indicate that self-twisting can affect the mechanical properties in specific directions of the structure, and also enhance the energy absorption capacity. Additionally, it mitigates the risk of structural collapse and failure during compression while diminishing structural anisotropy. The proposed self-twisting strategy, based on honeycomb lattice structures, has been proven valuable in advancing the investigation of lattice structures with largely tunable mechanical properties.

Haldane model with chiral edge states using a synthetic dimension

We explicitly show that the differences, with respect to the appearance of topological phases, between the traditional Haldane model, which utilizes a honeycomb lattice structure, and the Haldane model imbued onto a brick-wall lattice geometry are inconsequential. A proposal is then put forward to realize the Haldane model by exploiting the internal degrees of freedom of atoms as a synthetic dimension. This leads to a convenient platform for the investigation of chiral edge states due to the hard boundaries provided by the hyperfine manifold. We make some cursory comments on the effects of interactions in the system. Published by the American Physical Society 2024

On the plasmonic properties of a graphene nanoribbon and noble metal composite array

Graphene, composed of sp2 hybrid orbitals, is a hexagonal nanomaterial with a two-dimensional honeycomb lattice structure. Nowadays, thanks to its great electronic, optical, and thermal properties, there have been many promising applications based on graphene nanostructures. Under irradiations of external electromagnetic fields, the free electrons on graphene surfaces can be excited to oscillate collectively, resulting in highly localized surface plasmons. This phenomenon may provide foundations for designs of tunable plasmonic devices, therefore, graphene-based nanostructures have been widely studied so far. Besides, investigations on noble metals is another hot topic in the plasmonic community. With irradiations of incident lights, collective oscillations of free electrons on noble metals’ surfaces can also be induced, forming surface plasmons. The plasmonic characteristics can be adjusted by varying the parameters of the metals, including the geometries, thicknesses, as well as dimensions, etc. In this paper, a composite array consisting of graphene nanoribbons and noble metals is proposed, and its plasmonic properties are studied at mid-infrared wavelengths. In the structure, graphene nanoribbons are placed in between two SiO2 layers, and gold semi-cylinders and silver nanofilms are placed above the upper SiO2 layer, respectively. Using the finite difference time domain method, the light transmittance and electric field of the array are investigated, by varying the graphene’s Fermi energy and layer number, the noble metals’ sizes, as well as the period of the array, respectively. The results show that a plasmonic resonance feature is revealed in the 4–18 μm wavelength range, and the resonance characteristics can be tuned by adjusting the above parameters. The composite array structure proposed in this work may provide us with a new platform for the design of plasmonic devices in the mid-infrared regime.

Microstructured Organic Cavities with High‐Reflective Flat Reflectors Fabricated by Using a Nanoimprint‐Bonding Process

AbstractThe integration of photonic microstructure into organic microcavities represents an effective strategy for manipulating eigenstates of cavity or polariton modes. However, well‐established fabrication processes for microstructured organic microcavities are still lacking. This study proposes a nanoimprint‐bonding process as a novel fabrication method for microstructured organic microcavities. This process relies on a UV nanoimprint technique utilizing two different photopolymer resins, enabling the independent fabrication of highly reflective reflectors and photonic microstructures without compromising the accuracy of each. The resulting organic microcavities demonstrate spatially localized photonic modes within dot structures and their nonlinear responses on the pumping fluence. Furthermore, a highly precise photonic band is confirmed within a honeycomb lattice structure, which is owing to the high quality factor of the cavity achievable with the nanoimprint‐bonding process. Additionally, a topological edge state is also observable within a zigzag lattice structure. These results highlight the significant potential of the fabrication method for advancing organic‐based photonic devices, including lasers and polariton devices.

A topological approach for optimizing the dimensional properties of various bioinspired periodic type honeycomb latticed carbon fiber reinforced glycol‐modified poly (ethylene terephthalate) composite materials

AbstractThe present research efforts are directed toward investigating dimensional stability, focusing on bio‐inspired periodic honeycomb lattice structures within carbon fiber reinforced glycol‐modified poly ethylene terephthalate (PETG) composites. These samples are fabricated using extrusion‐based 3D printing, with topological parameters such as shell thickness (ST), unit cell type (UCT), wall thickness (WT), unit cell orientation (UCO), skewing angle (SA), and unit cell size (UCS) being manipulated across three different levels. The experimental findings indicate that achieving the lowest dimensional length error is attainable under specific conditions, including a smaller ST of 0.5 mm, a square UCT, a WT of 0.5 mm, a UCO of 90°, a SA of 0°, and a UCS of 4 mm. Analyzing the results with ANOVA reveals that UCT (28.82%) and WT (18.73%) exert the most significant influence on the dimensional stability response. The regression model closely aligns with experimental outcomes, with an error percentage of 3%, rendering it suitable for large‐scale customization. Under the optimized topological parameters, carbon fiber‐reinforced PETG latticed composites exhibited a dimensional length error of 0.292 mm and a compressive strength of 21.56 MPa. Fractography analysis revealed a brittle mode of fracture across all samples, indicating their stiffness and strength, especially when compared to samples with lower wall thickness. These findings suggest that the designed carbon fiber‐reinforced PETG latticed composite material holds potential for use in minor surgical orthotic and prosthetic applications.Highlights Bio‐inspired periodic honeycomb lattice structured PETG composites. Topological optimization on the dimensional properties. Taguchi optimization is performed on design‐based lattice structures. Unit cell type has highest contribution of 28.82% on dimensional properties.

Crashworthiness Evaluation of Electric Vehicle Battery Packs Using Honeycomb Structures and Explicit Dynamic Analysis

The battery pack system is crucial to safeguard battery units during any collision. The crashworthiness of battery packs could be improved with the incorporation of honeycomb structures. The objective of the current study is to evaluate the structural characteristics of battery encasing using ANSYS explicit dynamic analysis. The modal analysis is conducted to determine the natural frequency, mode shape, and peak displacement values. The CAD model of the battery pack is developed in Creo parametric design software. The use of a honeycomb structure enabled the reduction of the effect of impact on battery units. At the time of the collision, the honeycomb structure would absorb maximum crash impact and would save the battery unit cells from major damage. The natural frequency of a battery pack with a honeycomb structure has a higher first, 2nd, and 3rd natural frequency. At the time of impact and without any honeycomb structure, the internal energy of the battery unit is 1021.8mJ while with the honeycomb lattice structure, it is 0.80376mJ. The results have shown that with the incorporation of a honeycomb structure, there is a substantial reduction in the internal energy of the cell with the incorporation of the lattice structure.

Two-dimensional honeycomb lattice structure for underwater acoustic cloaking using pentamode materials

This research article presents an innovative and novel approach to achieve underwater acoustic cloaking using a two-dimensional honeycomb lattice structure with pentamode materials in the kHz frequency range. Underwater acoustic cloaking holds substantial importance in various applications, such as marine engineering, imaging, and military operations, making the development of an efficient underwater acoustic shell imperative. The proposed cloak consists of a pentamode titanium material honeycomb lattice embedded in an air background, submerged in water. To attain effective camouflage and regulate the phase and energy flow, impedance matching was applied to the overall geometry of the structure. By fine-tuning the structural parameters of the cloaking shell, derived from the effective mass velocity and density for recovering reflected waves, impedance matching with water was ensured. Through simulation calculations and optimization design, the average total scattering cross-section of the acoustic cloak is determined to be 0.1. The results demonstrate that the pentamode material-based cloaking approach is not only suitable and efficient in achieving the cloaking phenomenon but also enhances operator flexibility. The operating frequency bandwidth of the acoustic cloaking system is approximately 8 kHz for lattice constant a = 5 mm. These findings pave the way for further advancements in underwater acoustic cloaking technologies.

Melaminin Yerinde Polimerizasyonu ile Grafit Katmanlarının Genişletilmesi Üzerine Bir Çalışma

Graphene, renowned for its honeycomb lattice structure formed by densely packed sp2 hybridized carbon atoms, possesses exceptional electronic, thermal, chemical, and mechanical properties. The van der Waals-coupled graphene layers give rise to the well-known AB stacking, forming graphite. Despite the existence of several methods for graphite production, the production of graphene on a large scale remains challenging due to the lack of efficient techniques and the introduction of structural defects during the production process. Exfoliated graphite (EG), a potential solution, is typically derived from the thermal treatment of graphite intercalation compounds (GICs). Melamine, notably displaying significant expansion properties at low temperatures, has been used as an intercalation compound in limited studies. This study investigates the potential of melamine to induce the expansion of graphene layers when incorporated into graphite and subjected to thermal treatment. Raman and X-ray diffraction analyses were employed to assess structural changes.

Noise-Induced Defects in Honeycomb Lattice Structure: A Phase-Field Crystal Study

One of the classes of the kinetic phase-field model in the form of the two-mode hyperbolic phase-field crystal model (modified PFC model) is used for the study of the noise effect of the crystalline structure. Special attention is paid to the origin of the defect’s microstructure in the crystalline honeycomb lattice due to induced colored noise. It shows that the noise–time correlation coefficient τζ, comparable to the diffusion time, enhances the grain boundary mobilities. Instead, a small spatial correlation coefficient, λζ, close to the first lattice parameter of the honeycomb crystal, stabilizes the structure. The finite non-zero value of the relaxation time τ for the atomic flux significantly slows the local relaxation of the fluctuated field and leads to the grains’ fragmentation and formation of the disordered phases. The obtained results are applicable to the hexagonal atomic structures and, in particular, to honeycomb crystals, such as boron nitride, in which the lattice defects might be simulated through the induced colored noise.

Many Body Aspects on the Lattice Vibrational Properties of Germanene and Silicene along Highly Symmetry Directions

The investigation of lattice vibrational properties in monolayer two-dimensional honeycomb lattices comprising 2D group-IV semiconductor materials such as Germanene and Silicene (Low Buckled structure) holds immense significance in the realm of research, owing to their potential integration into the forthcoming electronic sector for information technology. The ductile nature of 2D group-IV semiconductor materials enables seamless integration with existing semiconductor technology on substrates, setting them apart from Graphene. Our primary objective revolves around comprehending the lattice vibrational properties of Germanene and Silicene (LB) through the examination of their honeycomb and buckled lattice structures. We use the Adiabatic Bond Charge Model with a Python program to derive vibrational frequencies at the Г points along highly symmetrical directions. Moreover, we extensively analyze the acoustical and optical contributions to the lattice vibrational frequencies. We anticipate that the phonon frequencies along the Г‒M direction for 2D atomically thin Germanene and Silicene will yield reasonably similar outcomes to those other research groups achieve.

Tailored Dispersion and Nonlinear Effects in Flint Glass Honeycomb PCF for Optical Communication

This paper describes a highly nonlinear flint glass-based honeycomb photonic crystal fiber (FGH-PCF) with a wavelength of 1550 nm. The PCF’s distinctive honeycomb lattice structure, combined with the nonlinear capabilities of flint glass, enables a wide range of nonlinear optical applications. To adjust the PCF's dispersion and nonlinear effects, numerical simulations and optimization approaches were used. To achieve maximum performance, fabrication procedures were carefully regulated. Dispersion values of −436.6 ps/(nm.km) for x polarization and −448.1 ps/(nm.km) for y polarization were verified by experimental characterization. The PCF displayed low confinement losses of 2.289 dB/cm (x polarization) and 4.935 dB/cm (y polarization), as well as birefringence of 2.202×10-3. The PCF measured 558.8 and 547.9 W-1 km-1 for x and y polarization, respectively, indicating a high nonlinear coefficient. The highly nonlinear FGH-PCF shows promising potential for nonlinear optical applications such as four-wave mixing, supercontinuum generation, frequency conversion, and parametric amplification. This research paves the way for compact and efficient nonlinear devices in modern optical communication systems and other cutting-edge technologies.

A low-threshold single-mode higher-order topological photonic crystal nanowire array laser

A higher-order topological photonic crystal GaAs/AlGaAs/GaAs nanowire array laser based on 0D corner modes is proposed and analyzed. The structure is composed of a nanowire trivial photonic crystal sandwiched by two topological photonic crystals. Compared with the conventional deformed honeycomb lattice photonic crystal structure, an additional mode selection mechanism is introduced by adjusting the coupling strength of topological cavities formed at two topological interfaces. By optimizing the structure parameters, a large side-mode suppression ratio of 24 dB and a high-quality factor of 7935 are obtained. Due to the strong mode confinement, lasing is achievable at an ultrasmall diameter of 86 nm, with a high confinement factor of 7.96 and low threshold gain of 230 cm−1. Moreover, the laser exhibits a small beam divergence of 6.6°. This work may pave a way for the development of low-threshold single-mode miniaturized lasers.