Hybridization Strength Research Articles

The scaled-invariant Planckian metal and quantum criticality in Ce1−xNdxCoIn5

The mysterious Planckian metal state, showing perfect T-linear resistivity associated with universal scattering rate, 1/τ = αkBT/ℏ with α ~ 1, has been observed in the normal state of various strongly correlated superconductors close to a quantum critical point. However, its microscopic origin and link to quantum criticality remains an outstanding open problem. Here, we observe quantum-critical T/B-scaling of the Planckian metal state in resistivity and heat capacity of heavy-electron superconductor Ce1−xNdxCoIn5 in magnetic fields near the edge of antiferromagnetism at the critical doping xc ~ 0.03. We present clear experimental evidences of Kondo hybridization being quantum critical at xc. We provide a generic microscopic mechanism to qualitatively account for this quantum critical Planckian state within the quasi-two dimensional Kondo-Heisenberg lattice model near Kondo breakdown transition. We find α is a non-universal constant and depends inversely on the square of Kondo hybridization strength.

The relationship between orbital hybridization and superconductivity of sm-doped YBa2Cu3O7–δ studied by x-ray spectroscopy

Sm-doped YBa2Cu3O7–δ samples were prepared by conventional solid state reaction method in air. The studies of X-ray photoemission spectroscopy and X-ray absorption spectroscopy indicate that the extra electrons fill the holes in CuO2 planes, so that the hole carrier concentration decrease under Sm substitution. The X-ray absorption spectroscopy of Cu L-edge and O K-edge demonstrates that the hybridization strength between Cu 3d and O 2p decreases with increasing content of Sm, but the hybridization strength between Y 4d, Ba 5d, Sm 4f and O 2p increases with the increasing of Sm content, while the superconductivity of the Sm-doped YBa2Cu3O7–δ samples is suppressed, i.e., the superconducting transition temperature of the samples was lowered. Thus, our experimental results suggest a close relationship between the superconductivity and orbital hybridization.

Mechanism of laser-inducing hierarchical surface structures improving bonding strength of metal-plastic hybrids

The mechanism of laser-inducing hierarchical metal surface structures was investigated both experimentally and numerically, providing insights into improving bonding strength of metal-plastic hybrids (MPHs). For this purpose, metal sheets were first treated with the nanosecond pulsed laser to induce surface microstructures, followed by being put into the mold cavity, and jointed with plastic via the injection molding process. Both aluminum and titanium alloys were adopted as the metals and the glass fiber reinforced polyphenylene sulfide was chosen as the plastic material for MPHs. Specifically, laser parameters including the scanning speed, laser frequency, scan repetition, and modulation switch pulse-width were varied to investigate their impact on metal surface microstructure morphology and thus the MPH bonding strength. It is found that although having no clear trend while changing the laser parameters, the MPH bonding strength is strongly dependent on both surface morphology and material type of the metals. Finally, the process was optimized based on observations concerning the laser-inducing mechanism. The titanium alloy surfaces with bumpy morphology facilitated forming microscale mechanical interlocking between the metal and the plastic, leading to enhanced MPH bonding strength.

Study of mechanical properties of the natural-synthetic fiber reinforced polymer matrix composite

In the era of competition and modernization of existing materials in advancement to their properties and their mechanical behaviour. The primary concern when it comes to improving the mechanical behaviour for the natural reinforced fiber polymer composites is that synthetic reinforced fiber polymer matrix composites will eventually replace them in numerous engineering applications. This study addresses the tensile strength of carbon fibre, jute fibre, and carbon fibre composite hybridization. The combination of natural and the synthetic fibres is essential for enhancing mechanical characteristics of a composite material. Carbon and glass, for example, are stiffer and stronger than natural fibres. The primary aim of this research is to improve composite material tensile strength by incorporating synthetic fibre into natural fibre. The point of the study is to evaluate the tensile behaviour of a composite material specimen. Using the ABAQUS software package, a carbon/jute fibre reinforced hybrid polymer composite was numerically constructed to assess the tensile behaviour of the composite samples. Experimental investigation of the composite laminate of the different materials is implemented using Hashin’s Criteria and Von mises stress for tensile simulation and It has been noticed that surface treatment of fibre can improve bonding between fibre and matrix. Natural fibre polymer composites with improved mechanical attributes are replacing synthetic fibre reinforced polymer matrix composites (PMCs) in wide range of commercial applications. According to the results, jute fibres have a lower tensile strength than the hybrid fiber-reinforced composite material. Addition of carbon fibre gradually increases the composite laminate's strength. We can obtain the tensile parameters of the materials and constituents by applying modelling to the experimental results.

Near- and Far-Field Optical Properties of Dipole-Multipole Plasmonic Coupled Building Blocks

The plasmonic hybridization in the complex nanostructure innovates multiple fields, such as chemistry, physics, materials science, and biology. In this article, we systematically studied the near- and far-field optical properties of building blocks of coupled dipoles or coupled dipoles and multipoles or a multipole in a coupled plasmonic system through numerical simulations. To be specific, the far-field spectrum, near-field phase changes, and angular radiation patterns of plasmonic hybridized structures were calculated. Also, the “gap separation effect” on the strength of plasmonic hybridization was discussed via spectral and near-field evaluation. Additionally, we investigated the coupling between building blocks and different shapes of dipoles through the near- and far-field study. To some extent, our studies have theoretically proven that, compared to the plasmonic coupling among dipoles, the coupling between multipoles and dipoles show mostly comparative and even stronger hybridization in terms of both near- and far-field, which led to the expanded broad range of resonance and stronger localized E-field. We believe that our work may contribute to the fundamental understanding of the plasmonic hybridization system and pave the path for new applications and opportunities in vast regimes of plasmonic-photonic and nanoplasmonic.

Mott physics: One of main themes in quantum materials

<sec>The competition and cooperation between the itinerancy behavior and localization behavior of electrons in correlated quantum materials, known as Mott physics, is the physical mechanism behind the diverse states of many quantum materials. This article reviews the manifestation of Mott physics in various quantum materials and establishes it as one of the main themes of quantum materials. Finding and understanding its ever-changing ways of manifestation is one of the central tasks of experimental research on condensed matter physics.</sec><sec>Specifically, the filling-control route of Mott transition is illustrated by exampling the surface K-dosed Sr<sub>2</sub>IrO<sub>4</sub>, which exhibits d-wave gap, pseudogap behavior in underdoped regime, and phase separation with inhomogeneous electronic state distribution. All of these show strong resemblances to the doped cuprate superconductors, another prototypical filling-control type of Mott transition case. On the other hand, the bandwidth-control route of Mott transition could be found in NiS<sub>2–<i>x</i></sub>Se<sub><i>x</i></sub>, where its bandwidth continuously decreases with decreasing Se concentration, until it becomes an insulator. In addition, the essence of various ways of doping in iron-based superconductors is to change their bandwidths. The superconductivity shows up at intermediate bandwidth with moderate correlations, and it diminishes when the bandwidth is large and the electron correlations are weak. For heavily electron-doped iron-selenides, there is even a Mott insulator phase with strong correlations.</sec><sec>For carbon based materials, the phase transition between the antiferromagnetic insulator and superconducting state of A15 Cs<sub>3</sub>C<sub>60</sub> as the volume of fullerene anions decreases could be understood in terms of a bandwidth-control Mott transition; the insulator-superconductor transition discovered in electrically gated “magic angle” twisted-angle bilayer graphene could be understood as a filling-control Mott transition.</sec><sec>For f electron systems, the interplay between itinerancy and localization dominates the heavy fermion behavior and their ground states. The behaviors of the f electrons are demonstrated by using the angle-resolved photoemission data of CeCoIn<sub>5</sub>, whose f electron band becomes more coherent with decreasing temperature, and the c-f hybridization is thus enhanced and the band mass of conduction band continuously increases. The c-f hybridization behaviors of CeCoIn<sub>5,</sub> CeIrIn<sub>5</sub>, and CeRhIn<sub>5</sub> are compared with each other, and the differences in hybridization strength put their ground states into different regimes of the Doniach phase diagram. Similarly, the Skutterudites 4f<sup>2</sup> Kondo lattice system PrOs<sub>4</sub>Sb<sub>12</sub> and its sibling 4f<sup>1</sup> system CeOs<sub>4</sub>Sb<sub>12</sub> also have different ground states due to a slight difference in their c-f hybridization strengths.</sec>

Physical characteristics of maize seeds and their technological significance in processing and storage of sowing material

Topicality. The research on the preparation of high-quality seed of maize hybrids based on the consideration of their technical and technological properties at the stages of harvesting, processing and storage is relevant today. Purpose. To study and determine the essential physical parameters that characterise technical and technological characteristics and affect the seed quality of maize hybrids. Methods. The research includes theoretical and practical calculations with a review of literature sources, laboratory and model experiments and the laying out of field trials, mathematical and statistical evaluation of the data obtained. The experiments were carried out according to standardised methods of DSTU and agrotechnical recommendations, and the source material was hybrids bred by the State Enterprise Institute of Grain Crops of the National Academy of Agrarian Sciences of Ukraine. Results. The most significant physical characteristics of seeds are evaluated: shape, linear size, volume and geometric surface of seeds, their weight and specific weight, mechanical strength of maize hybrids and self-pollinated lines, and differences between them are determined. Experiments on seed separation, drying and storage were carried out, and certain physical characteristics were identified that have a special impact on the technology of these processes and form the seed quality. Conclusions. The dry seed quality during the separation process is most affected by the linear size of the seed, in particular, seed width, depending on which the fractions with the highest germination and yield are separated (tailing through round holes of 8 mm and more in diameter). Drying is influenced by the coefficient that characterises the ratio of the geometric area to the volume of the seed; at a coefficient of more than 1.0 (in experiments – 1.14–1.22), the intensity of moisture transfer and the drying rate increase by 8.3–15.7 % compared to a coefficient of 1.0. During storage, especially long-term storage, the quality and resistance of seeds is affected by the equilibrium moisture content, which should be at the level of 12 %, depending on the environmental conditions. Key words: maize seed, harvesting, drying, storage, physical characteristics, germination, yield

Design Provisions for Flexural Strength of Hybrid Reinforced Concrete Beams with Fiber-Reinforced Polymer and Steel Bars

Design Provisions for Flexural Strength of Hybrid Reinforced Concrete Beams with Fiber-Reinforced Polymer and Steel Bars

Controlling the strong light-matter coupling in metal-dielectric optical resonators using spin-crossover molecules

We report the observation of (ultra)strong light-matter coupling, in the UV spectral region, between optical modes of a metal/dielectric bilayer nanocavity and the electronic excitations of spin-crossover (SCO) molecules. By thermally switching the SCO molecules between their low-spin and high-spin states, we demonstrate the possibility of fine-tuning the light-molecule hybridization strength, allowing a reversible switching between strong- (with Rabi splitting values of up to 550 meV) and weak-coupling regimes within a single photonic resonator. As a result, we show that spin-crossover molecular compounds constitute a novel, promising class of active nanomaterials in the context of tuneable and reconfigurable polaritonic devices.

Study of genetic analysis of individual hybrids derived by the half-diallel cross of some Lycopersicon esculantum mill

The study was conducted for the first season of 2020 in the field of the College of Agriculture \ Diyala University which the seeds of the first generation F1 hybrids were produced for six strains that were selected according to the genetic distance among them and resulted in 15 hybrids by applying for the half diallel crossing program. In the second year, the seeds of individual hybrids were planted with their parents and a hybrid Commercial common boob cat for comparison within a field experiment to evaluate the field performance of these produced hybrids according to the design of complete randomized sectors and with three replications. The differences were tested according to the LSD test. The result showed that the highest hybrid strength compared with the highest parents for the trait of plant height 43.34 cm, number of fruits 48.20%, plant yield 77.27%, TSS ratio 41.83%, fruit content of vitamin C 33% and sugar content 25.86% for the above traits, respectively. As for the common commercial hybrid, Boob cat was 64.20%, 121.23%, 43.92%, 55%, 109.36% and 46.65%, respectively. As for the union ability, the father gave c.c. Orang (5) had the highest general combined ability for plant height which amounted to 3.972. For the number of fruits, plant yield and TSS, Father Rose (1) showed the highest general union ability, which amounted to 4.136, 0.358 and 0.095, respectively, while the vitamin C and sugars ratio were recorded by the fathers (5) Red P.t (2) and Amish Pa.(4). The highest general federating ability amounted to 1.937 and 0.975 respectively while the highest union ability for plant height in 1×5 hybrids reached 33.375 and for TSS and sugars the hybrid showed1×3The highest ability of a particular union was 1.60 and 1.77, respectively. Regarding the characteristics of fruit number and yield of a plant, the 1×2 hybrid was superior in a proportion of 16.71 and 1.11 for vitamin C, and the 3×4 hybrid was superior in a ratio of 8.06. As for the percentage of heritability was high compared to the strict sense, indicating the importance of non-host gene action of genes in the inheritance and manifestation of the trait. The mean of the degree of dominance was higher than one for all the mentioned traits, which evidences the participation of super dominance of genes in the manifestation of the trait. Keywords: half-diallel, boob cat, genetic distance, Lycopersicon esculantum

Impact ionization processes in a photodriven Mott insulator: Influence of phononic dissipation

We study a model for photovoltaic energy collection consisting of a Mott insulating layer in presence of acoustic phonons, coupled to two wide-band fermion leads at different chemical potentials and driven into a nonequilibrium steady state by a periodic electric field. We treat electron correlations with nonequilibrium dynamical mean-field theory (DMFT) using the so-called auxiliary master equation approach as impurity solver and include dissipation by acoustic phonons via the Migdal approximation. For a small hybridization to the leads, we obtain a peak in the photocurrent as a function of the driving frequency which can be associated with impact ionization processes. For larger hybridizations the shallow peak suggests a suppression of impact ionization with respect to direct photovoltaic excitations. Acoustic phonons slightly enhance the photocurrent for small driving frequencies and suppress it at frequencies around the main peak at all considered hybridization strengths.

Influence of CVI process time on the C-ring strength of hybrid SiCf/SiC composites fabricated by CVI–LSI

Influence of CVI process time on the C-ring strength of hybrid SiCf/SiC composites fabricated by CVI–LSI

Pressure-driven change of ground state of Ce3Pd3Bi4 : A DFT+DMFT study

A candidate material for strongly correlated topological materials, ${\mathrm{Ce}}_{3}{\mathrm{Pd}}_{3}{\mathrm{Bi}}_{4}$ has attracted much attention, but its ground state remains controversial. Compared with the typical Kondo insulator ${\mathrm{Ce}}_{3}{\mathrm{Pt}}_{3}{\mathrm{Bi}}_{4}$, two possibilities of ground states are proposed: ${\mathrm{Ce}}_{3}{\mathrm{Pd}}_{3}{\mathrm{Bi}}_{4}$ is either a spin--orbit-driven topological semimetal or a Kondo insulator with less Kondo coupling strength than platinum. Here, we performed density functional theory $(\mathrm{DFT})+\mathrm{dynamical}$ mean field theory (DMFT) calculations on ${\mathrm{Ce}}_{3}{\mathrm{Pd}}_{3}{\mathrm{Bi}}_{4}$ under different pressures to clarify its ground state, as pressure can tune the strength of Kondo coupling without affecting the strength of spin-orbit coupling. We found ${\mathrm{Ce}}_{3}{\mathrm{Pd}}_{3}{\mathrm{Bi}}_{4}$ has a metallic ground state and becomes insulating with increasing pressure at a low temperature. And as the pressure increased to 2 GPa, a hybridization energy gap can be observed at 10 K. As the pressure increased to 5 GPa, the electronic structure of ${\mathrm{Ce}}_{3}{\mathrm{Pd}}_{3}{\mathrm{Bi}}_{4}$ is even similar to that of the Kondo insulator ${\mathrm{Ce}}_{3}{\mathrm{Pt}}_{3}{\mathrm{Bi}}_{4}$ under ambient pressure, and a clear hybridization energy gap $(\ensuremath{\sim}3\phantom{\rule{0.28em}{0ex}}\mathrm{meV})$ appears at 20 K. Our results not only demonstrate that the key factor controlling the different ground states between the two compounds is Kondo physics, rather than spin-orbit coupling, but also confirm that ${\mathrm{Ce}}_{3}{\mathrm{Pd}}_{3}{\mathrm{Bi}}_{4}$ is an ideal material to tuning the ground states by changing the strength of hybridization by pressure.

Influence of the proportion of FRP to steel reinforcement on the strength and ductility of hybrid reinforced concrete beams

The present study pertains to the influence of variation of FRP (Fiber Reinforced Polymer) proportion in tension reinforcement on the flexural behavior of RC beams with FRP and steel reinforcing bars. A total of 25 beams, including FRP-, steel- and hybrid FRP-steel reinforced ones, were tested to failure under four-point bending. Two types of FRP bars, GFRP (Glass Fiber Reinforced Polymer) and BFRP (Basalt Fiber Reinforced Polymer), were used and both over- and under-reinforced beams were tested. The beams in each group were designed to have close flexural capacities to fully reveal the effect of FRP proportion in the tension zone on beam ductility for a fixed bending capacity. A new analytical model was developed for estimating the bending capacities of beams. Different deformation and curvature ductility definitions were adopted and an energy-based definition, revealing the expected tendency in beam ductility, was determined. The test results revealed that the presence of even a single FRP bar in the tension zone results in reductions up to 40% in beam ductility as compared to the beam with full steel reinforcement. Each additional replacement of a steel bar with FRP was found to cause a further decrease up to 20% in beam ductility.

Prediction of Axial Compressive Strength of Hybrid Reinforced Concrete Columns under Static Loading

Prediction of Axial Compressive Strength of Hybrid Reinforced Concrete Columns under Static Loading

Combined effect of tungsten inert gas welding and roller expansion processes on mechanical and metallurgical characteristics of heat exchanger tube-to-tubesheet joints

Tube-to-tubesheet joints are one of the major vulnerable locations prone to cracks in heat exchangers. The manufacturing processes of these joints have an important role in providing structural integrity to the heat exchangers. The main objective of this work is to study the impact of the combined effect of tungsten inert gas weld and expansion percentages of 3%, 5% and 7% on the structural integrity of carbon steel-based tube-to-tubesheet joints. The results show that the pull-out strength of hybrid welded and expanded using 3%, 5% and 7% expansion percentages has exceeded the tube axial strength. The minimum leak path of the welds was satisfactorily above two-thirds of the tube wall thickness. Vickers hardness was restricted at the adjacent regions of weld to below 250 HV. The microstructural studies indicate that the higher the expansion percentage, the smaller the grains at the inner tube surface and the higher the extent the fine grains formed from the inner tube surface. The effect of expansion on the grains at the inner and outer tube surfaces of the transition zone and the unexpanded zone was found negligible. The absence of grain refinement on the outer tube surface using light expansion at a 3% expansion percentage indicated that the contact pressure was inadequate on the tube-to-tubesheet interface. The hardness at the expanded zone and transition zone of the inner tube surface was higher than at the outer tube surface due to the plastic deformation caused by the intensive roller expansion pressure.

Direct observation of the hybridization gap in both the hidden order and large moment antiferromagnetic phases in URu2Si2

Despite extensive research on the heavy fermion superconductor $\mathrm{U}{\mathrm{Ru}}_{2}{\mathrm{Si}}_{2}$ in the past three decades, the nature of the hidden order (HO) phase transition occurring at 17.5 K remains ambiguous. Here we report a comparative scanning tunneling microscopy/spectroscopy (STM/STS) study on different terminations of the parent $\mathrm{U}{\mathrm{Ru}}_{2}{\mathrm{Si}}_{2}$ and Fe-doped samples. A small gap, which was ascribed to the HO parameter by previous STM/STS studies, emerges in both the HO and large moment antiferromagnetic phases on the U terminations, indicating it is not the unique hallmark of the HO parameter. Moreover, a peak-gap-peak structure is observed on the Si terminations. Variations of the two spectral features with Fe concentration and temperature show that they stem from the alteration of $f\text{\ensuremath{-}}c$ hybridization. The higher vanishing temperatures and larger sizes of the gap in the Fe-substituted samples indicate stronger $f\text{\ensuremath{-}}c$ hybridization strength compared to $\mathrm{U}{\mathrm{Ru}}_{2}{\mathrm{Si}}_{2}$. Our studies demonstrate hybridization is not the driving force for the HO phase transition.

Electronic structure studies of Kondo lattice compounds CeRhSn[formula omitted] and CeRuSn[formula omitted]: Comparative study

We report on X-ray photoelectron spectroscopy and ab initio electronic structure investigations of CeRuSn3 and CeRhSn3 and their La counterparts. A combined experimental study and band structure calculations indicate a stable configuration of Ce3+ in the both Ce-based compounds. We also documented that the transition metal Rh or Ru with different number of 4d electrons plays a decisive role in controlling the hybridization strength V between the 4f and conduction electron states, which in turn governs the magnetic ground state properties of these compounds. For CeRuSn3V is ∼1.2 times larger than V of CeRhSn3, which is a reason of stronger Kondo interaction in Ru sample, expressed by larger Kondo temperature TK. On the basis of Schrieffer–Wolff transformation, ab initio calculations, and XPS data, we estimated on-site Jfc coupling constants, which are dependent on Wyckoff position of Ce, and allowed to determine Kondo temperatures, as well as explain nature of the magnetic ground states. The interband hybridization forms a pseudogap in the density of states of CeRuSn3, CeRhSn3 and their La-bearing counterparts at the Fermi level, which could be a reason of Mott variable-range hoping behavior.

Mechanical properties of all-C/C composite hybrid bonded/bolted joints

In this paper, experiments and numerical simulations were used to study the mechanical properties of all-C/C composite hybrid bonded/bolted joints. Experiments were conducted to investigate the failure mechanisms, modes, and strengths of composite single-lap joints, namely, bolted joints with and without bonds. The results demonstrated that the failure mode of all-C/C composite mechanical joints was bolt shear failure, while the failure mode of the bonded joints was cohesive force failure. In hybrid bonded/bolted joints, cohesive force failure of the adhesive layer and bolt shear failure have both been noted. The C/C composite plates of all joints were not discovered to have any evident deterioration. The load-displacement curve of the hybrid joints was a double-peak curve, the first peak load corresponds to bonding failure, and the second peak load corresponds to bolt failure. For the failure process, mode, and strength of hybrid (bonded/bolted) joints, a 3D progressive damage finite element model was proposed. It is based on the nonlinear finite element code ABAQUS and Hashion failure criteria. The VUMAT subroutine compiled Hashion failure criteria to simulate the damage of fiber and matrix in the composite material. Furthermore, the adhesive layer’s failure was simulated using the cohesive element. Comparing failure loads and failure modes to the outcomes of experiments served to validate the model. The gradual damage evolution process and failure mechanism of bonded and hybrid bonded/bolted joints were determined, as well as the mechanism by which the cohesive layer influences the mechanical properties of the hybrid bonded/bolted joints. On the mechanical characteristics of composite joints, the impacts of bolt diameter and adhesive layer modulus were investigated.

Quantum dot scanning tunneling microscopy for Majorana bound states in continuum

We propose a device composed of a quantum dot (QD) connected to a normal metal lead to detect Majorana bound states (MBSs), which are formed at the ends of a topological superconductor nanowire (TSNW) and coupled to the lead with spin-dependent hybridization strengths. The information of the MBSs leaked into the lead is inferred from the spectral function of the QD serving as the tip of a scanning tunneling microscope (STM). It is found that lead–MBSs interaction induces a bound state characterized by an infinitely high peak in the dot’s zero-energy spectral function. The overlap between the two modes of the MBSs turns this bound state into a resonant one, and thus the zero-energy peak is split into three with the height of the central one equaling that in the absence of lead–MBSs coupling. We also find that the MBSs have lower impacts on the additional peak in the dot’s spectral function induced by intradot Coulomb interaction.