Symmetry Analysis Research Articles

The role of coherent nano precipitates on stacking fault and deformation twin formation during tensile deformation of wire arc additive manufactured nickel-aluminum-bronze

The strain hardening mechanisms and dislocation interactions of a wire arc additively manufactured (WAAM) nickel-aluminum-bronze (NAB) alloy was investigated using multi-scale characterization approach cross-correlating scanning electron microscopy (SEM), SEM-based electron back-scatter diffraction (EBSD), site- and crystallographic orientation-specific focused ion beam (FIB) nanofabrication, scanning transmission electron microscopy (STEM) and STEM-based energy dispersive X-ray spectroscopy (EDS). Flat, rectangular dog bone specimens were strained under uniaxial tension conditions. To understand the micro- and nanometer scale deformation mechanisms throughout the microstructure, tensile test specimens were interrupted near the yield strength and ultimate tensile strength. STEM microstructural characterization revealed that tensile deformation occurs by planar slip and multiple slip bands interacting on different {111} planes as well as the nucleation of dislocations from the interfaces associated with grains and secondary phase particles. To the authors knowledge for the first time the Center of symmetry (COS) analysis revealed that in both samples the shearing of nanoscale precipitates led to the formation of extended stacking faults including a combination of intrinsic stacking faults and 2-layer extrinsic stacking faults. At high strain levels more dislocations and stacking faults were nucleated, as well as intersecting slip bands further facilitating the activation of the stair-rod cross-slip mechanism and thickening of an ESF to create a 3-layer nano-twin. Activated mechanisms of plastic deformation and associated role of the precipitates are discussed with respect to the microscopic strength-plasticity characteristics as well as macroscopic mechanical properties of WAAM NAB alloy.

Comparing the compression behavior of the antiperovskites CePt3Si, CePt3B, and YPt3B from combined X-ray diffraction experiments and density functional theory

In this study we report the synthesis three antiperovskites YPt3B, CePt3B, and CePt3Si as well a focused investigation of YPt3B, which all have the same P4mm symmetry with a large c∕a ratio at ambient conditions. The compounds are investigated under high-pressure using powder X-ray diffraction in diamond anvil cells. A structural transition is found to occur in the YPt3B compound at 23(2) GPa caused by the softening of a zone boundary phonon. Using a combination of symmetry analysis and structural prediction, the high-pressure phase is assigned to a structure described by the P2 (P121) space group. Calculation of the phonon dispersion confirms that this structure is dynamically stable with A = Ce, Y and Z = Si, B. It was found that the three APt3Z compounds behave differently with pressure. The bulk moduli for the three compounds are found to be 185(5) GPa, 155(3) GPa, and 128(2) GPa for YPt3B, CePt3B, and CePt3Si, respectively. We found that the Z atom moves away from the center with pressure for A = Ce along the c axis, whereas for A = Y, the Z atom stays in the approximately same position. This behavior is also reflected in their c∕a ratio which stays approximately constant in YPt3B. Overall we find that the Ce-bearing compounds are more compressible in the ab plane, reducing the tilting of the octahedra. As a result, in YPt3B and CePt3B the transition to the structure described by the P2 space group is likely to occur at higher pressures.

Topological edge states of acoustic zigzag tubes with triangle scatterers

Tubular geometries in phononic crystals have the advantages of hosting topological edge states without breaking the underlying symmetry of the lattice. The topological relationships between the acoustic zigzag tubes and the dispersion relation of the planar phononic crystal with a zigzag edge boundary are theoretically revealed through 2D k space analysis, circumferential pressure analysis, and lattice symmetry analysis. New cutting lines of the tubes are obtained, which link the winding number of the tubes with the dispersion relation of topological edge states in the planar phononic crystal. The eigenstates analysis shows that the circumferential periodic number of a tubular edge state is regular and corresponds to a specific wavenumber in the circumferential direction. On the basis of the unveiled topological relationships, tubular edge states with tunable properties are obtained by controlling the characteristic length of the boundary scatterers. Moreover, the tubular edge states are confirmed to be highly confined and robust along the designed transmission channel. This study may present a new way to design acoustic tubes with tunability and have potential applications in robust wave propagation and miniaturized phononic devices.

Pressure-induced magnetic and topological transitions in non-centrosymmetric MnIn2Te4

In recent years, the study of magnetic topological materials, with their variety of exotic physics, has significantly flourished. In this work, we predict the interplay of magnetism and topology in the non-centrosymmetric ternary manganese compound MnIn2Te4under external hydrostatic pressure, using first-principles calculations and symmetry analyses. At ambient pressure, the ground state of the system is an antiferromagnetic insulator. With the application of a small hydrostatic pressure (∼0.50 GPa), it undergoes a magnetic transition, and the ferromagnetic state becomes energetically favorable. At ∼2.92 GPa, the ferromagnetic system undergoes a transition into a Weyl semimetallic phase, which hosts multiple Weyl points in the bulk. The presence of non-trivial Weyl points have been verified by Wilson bands computations and the presence of characteristic surface Fermi arcs. Remarkably, we discover that the number of Weyl points in this system can be controlled by pressure and that these manifest in an anomalous Hall conductivity (AHC). In addition to proposing a new candidate magnetic topological material, our work demonstrates that pressure can be an effective way to induce and control topological phases, as well as AHC, in magnetic materials. These properties may allow our proposed material to be used as a novel pressure-controlled Hall switch.

Analysis of Lie symmetry, bifurcations with phase portraits, sensitivity and diverse W − M-shape soliton solutions for the (2 + 1)-dimensional evolution equation

This research investigates the Kadomtsev-Petviashvili-Benjamin-Bona-Mahony (KP-BBM) equation, a key model in nonlinear wave dynamics, particularly for shallow water waves. By integrating the features of the KP and BBM equations, it offers a comprehensive framework for studying the propagation, stability, and interactions of long waves. Using Lie group analysis for symmetry reductions and bifurcation with phase portraits to explore dynamic behaviour, the study also applies chaos theory to examine system features. Additionally, the new extended direct algebraic method (NEDAM) is employed to derive novel soliton solutions, including dark, bright-dark, W-shape, singular, periodic, and mixed forms. Sensitivity analysis is performed, and 3D, 2D, contour, and density plots visually demonstrate the results. These findings show that NEDAM effectively extracts exact solitons, providing a basis for further studies in nonlinear wave theory and its applications in engineering and physics.

Lie symmetry analysis, traveling wave solutions and conservation laws of a Zabolotskaya-Khokholov dynamical model in plasma physics

This article analyzes the analytic and solitary wave solutions of the one-dimensional Zabolotskaya-Khokholov (ZK) dynamical model which provides information about the propagation of sound beam or confined wave beam in nonlinear media and studies of beam deformation. By the Lie symmetry analysis method, we acquire the vector fields, commutation relations, optimal system, reduction, and analytic solutions to the specified equation by exerting the Lie group method. Moreover, the solitary wave solutions of the ZK model are procured by exerting the new auxiliary equation method (NAEM). The behavior of the acquired outcomes for several cases is exhibited graphically through two and three-dimensional dynamical wave profiles. Furthermore, the conservation laws of the ZK model are acquired by Ibragimov’s new conservation theorem.

Accessing bands with extended quantum metric in kagome Cs 2 Ni 3 S 4 through soft chemical processing

Flat bands that do not merely arise from weak interactions can produce exotic physical properties, such as superconductivity or correlated many-body effects. The quantum metric can differentiate whether flat bands will result in correlated physics or are merely dangling bonds. A potential avenue for achieving correlated flat bands involves leveraging geometrical constraints within specific lattice structures, such as the kagome lattice; however, materials are often more complex. In these cases, quantum geometry becomes a powerful indicator of the nature of bands with small dispersions. We present a simple, soft-chemical processing route to access a flat band with an extended quantum metric below the Fermi level. By oxidizing Ni-kagome material Cs 2 Ni 3 S 4 to CsNi 3 S 4 , we see a two orders of magnitude drop in the room temperature resistance. However, CsNi 3 S 4 is still insulating, with no evidence of a phase transition. Using experimental data, density functional theory calculations, and symmetry analysis, our results suggest the emergence of a correlated insulating state of unknown origin.

Identifying and quantifying potentially problematic prescribing cascades in clinical practice: A mixed‐methods study

AbstractBackgroundA prescribing cascade occurs when medication causes an adverse drug reaction (ADR) that leads to the prescription of additional medication. Prescribing cascades can cause excess medication burden, which is of particular concern in older adults. This study aims to identify and quantify potentially problematic prescribing cascades relevant for clinical practice.MethodsA mixed‐methods study was conducted. First, prescribing cascades were identified through literature search. An expert panel (n = 16) of pharmacists and physicians assessed whether these prescribing cascades were potentially problematic. Next, a cohort study quantified potentially problematic prescribing cascades in adults using Dutch community pharmacy data for the period 2015–2020. Additionally, the influence of multiple medications potentially causing the same ADR was evaluated. Prescription sequence symmetry analysis was used to calculate adjusted sequence ratios (aSRs), adjusting for temporal prescribing trends. An aSR >1.0 indicates the occurrence of a prescribing cascade. In a subgroup analysis, aSRs were calculated for older adults.ResultsSeventy‐six prescribing cascades were identified in literature and three were provided by experts. Of these, 66 (83.5%) were considered potentially problematic. A significant positive aSR for the medication sequence was found for 41 (62.1%) of these prescribing cascades. The highest aSR was found for amiodarone potentially causing hypothyroidism treated with thyroid hormones (4.63 [95% confidence interval 4.40–4.85]), based on 565 incident users. The biggest population (n = 34,645) was found for angiotensin converting enzyme‐inhibitors potentially causing urinary tract infections treated with antibiotics. Regarding four potential ADRs, the aSRs were higher for people using multiple medications that cause the same ADR as compared to people using only one of those medications. Among older adults the aSRs remained significant for 37 prescribing cascades.ConclusionAn overview was generated of potentially problematic prescribing cascades relevant for clinical practice. These results can support healthcare providers to intervene and reduce medication burden for older adults.

Enhancing operational performance assessment of structures with seismic response modification devices: The role of observability and symmetry analysis under limited sensor deployment

AbstractTo manage structural responses under various external forces, the increasing incorporation of seismic isolation and supplementary damping systems in modern civil engineering necessitates post‐installation performance assessments. The challenge of accurately inferring system information from these complex dynamical structures, especially with limited sensor deployment, could be significant. From the perspective of solving inverse problems, this challenge hinges on constructing an input‐output mapping that assures unique solutions, achievable through theoretical observability or symmetry analysis. We introduce a unified algorithm framework designed to accommodate various definitions of Lie derivatives, specifically for observability and symmetry analysis in dynamic systems with affine, non‐affine, and unknown inputs—capabilities not fully achieved in previous studies. We demonstrate its application across typical dynamic scenarios, including both linear and nonlinear examples. We also present a numerical example featuring complex isolation systems with limited sensor layouts, illustrating how uniform convergence can be achieved in estimating all system states when an observable input‐output mapping is utilized. Furthermore, an experimental example employing shaking table tests showcases the potential complications that arise when an unobservable input‐output mapping is used.

Ideal quadratic nodal point in half-Heusler semimetal LaPtBi

The research focus on topological states in electronic systems has recently expanded from traditional linear dispersions to encompass higher-order dispersions. These higher-order dispersions exhibit unique physical properties, including high topological charge, exotic magnetoresponse, and novel transport behaviors. In this study, we employ first-principles calculations to propose the half-Heusler material LaPtBi as an ideal quadratic nodal point semimetal. Our comprehensive analysis of the band structure reveals an ideal nodal point located precisely at the Fermi level, exhibiting quadratic dispersion in all directions. This finding is supported by symmetry analysis and effective model arguments. Moreover, when the spin-orbit coupling effect is considered, the nodal point transitions from triple to quadruple degeneracy, while maintaining its quadratic dispersion. The material also features multiple prominent arc surface states originating from the nodal point, which are distinctly separated from the bulk bands. This separation facilitates experimental verification. Overall, LaPtBi, with its quadratic nodal point and advantageous properties, serves as an ideal platform for further research. The study of this material is expected to enhance our understanding of higher-order topological states in electronic systems, potentially driving future advancements in the field.

Intrinsic Ferroelectric Switching in Two-Dimensional α-In2Se3.

Two-dimensional (2D) ferroelectric semiconductors present opportunities for integrating ferroelectrics into high-density ultrathin nanoelectronics. Among the few synthesized 2D ferroelectrics, α-In2Se3, known for its electrically addressable vertical polarization, has attracted significant interest. However, the understanding of many fundamental characteristics of this material, such as the existence of spontaneous in-plane polarization and switching mechanisms, remains controversial, marked by conflicting experimental and theoretical results. Here, our combined experimental characterizations with piezoresponse force microscope and symmetry analysis conclusively dismiss previous claims of in-plane ferroelectricity in single-domain α-In2Se3. The processes of vertical polarization switching in monolayer α-In2Se3 are explored with deep-learning-assisted large-scale molecular dynamics simulations, revealing atomistic mechanisms fundamentally different from those of bulk ferroelectrics. Despite lacking in-plane effective polarization, 1D domain walls can be moved by both out-of-plane and in-plane fields, exhibiting avalanche dynamics characterized by abrupt, intermittent moving patterns. The propagating velocity at various temperatures, field orientations, and strengths can be statistically described with a universal creep equation, featuring a dynamical exponent of 2 that is distinct from all known values for elastic interfaces moving in disordered media. This work rectifies a long-held misunderstanding regarding the in-plane ferroelectricity of α-In2Se3, and the quantitative characterizations of domain wall velocity will hold broad implications for both the fundamental understanding and technological applications of 2D ferroelectrics.

On the Construction of Congruences over Generalized Fuzzy G-Acts

Group action is defined to support Cayley’s claim that every group is isomorphic to a suitable subgroup of a symmetric group. Group actions have a wide range of applications, including the analysis of symmetries of geometric objects and algorithms and cryptographic systems. In 1965, Zadeh introduced the concept of fuzzy sets and provided a mathematical formulation for various concepts in this area. Since then, the concept of fuzziness has been integrated into several branches of mathematics to address the uncertainties of real-life scenarios. This article introduces the concept of group action in a fuzzy environment, termed fuzzy G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document}-subacts. The study provide the concept of fuzzy G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document}-orbits and fuzzy G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document}-stabilizers and clearly outlines fuzzy permutation representations of G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document} and fuzzy G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document}-morphisms. The research findings significantly contributes to the understanding of fuzzy G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document}-congruences and fuzzy quotient G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document}-subacts with the help of fuzzy G\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal {G}$$\\end{document}-partitions. This approach not only refines the underlying theories but also opens up new possibilities for practical implementation. Thus, the study demonstrates how the more complex fuzzy theory can expand and enrich the mathematical structures of abstract algebra, making them highly applicable.

Editorial for the Special Issue of “Fractional Differential and Fractional Integro-Differential Equations: Qualitative Theory, Numerical Simulations, and Symmetry Analysis”

Editorial for the Special Issue of “Fractional Differential and Fractional Integro-Differential Equations: Qualitative Theory, Numerical Simulations, and Symmetry Analysis”

Lie Symmetry Analysis and Explicit Solutions to the Estevez–Mansfield–Clarkson Equation

Lie Symmetry Analysis and Explicit Solutions to the Estevez–Mansfield–Clarkson Equation

Residual Symmetry and Interaction Solutions of the (2+1)-Dimensional Generalized Calogero–Bogoyavlenskii–Schiff Equation

In this paper, we investigate the (2+1)-dimensional generalized Calogero–Bogoyavlenskii–Schiff (gCBS) equation by using the residual symmetry analysis and consistent Riccati expansion (CRE) method, respectively. The residual symmetry of the gCBS equation is localized into a Lie point symmetry in a prolonged system and a new Bäcklund transformation of this equation is obtained. By applying the standard Lie symmetry method to the prolonged gCBS system, new symmetry reduction solutions of the gCBS equation are obtained. The gCBS equation is proved to be CRE integrable and new Bäcklund transformations of it are obtained, from which interaction solutions between solitons and periodic waves are generated and analyzed.

Study of singly anti-charmed pentaquark production in b-factory* *Supported in part by the Youth Foundation of China University of Mining and Technology (JN210003)

The b-factories, such as BelleII, BarBar, and LHCb, emphasize the increasing importance of exotic hadron research. In this paper, we discuss the possible production of singly anti-charmed pentaquark states from B mesons in a b-factory under (3) symmetry analysis. Discussions of both possibilities have been driven by the hypothesis that the pentaquark state considered in this work, known as the lowest lying state , could be bound or unbound. We find the golden channels for the production of the pentaquark ground states, such as . We further estimate the branching ratios for the production of the ground states from B meson decays. Thus, multiple channels are available for experiments, which may remove certain obstacles to the discovery of new pentaquark states.

Non-relativistic torque and Edelstein effect in non-collinear magnets

The Edelstein effect is the origin of the spin-orbit torque: a current-induced torque that is used for the electrical control of ferromagnetic and antiferromagnetic materials. This effect originates from the relativistic spin-orbit coupling, which necessitates utilizing materials with heavy elements. Here, we show that in magnetic materials with non-collinear magnetic order, the Edelstein effect and, consequently, a current-induced torque can exist even in the absence of the spin-orbit coupling. Using group symmetry analysis, model calculations, and realistic simulations on selected compounds, we identify large classes of non-collinear magnet candidates and demonstrate that the current-driven torque is of similar magnitude as the celebrated spin-orbit torque in conventional transition metal structures. We also show that this torque can exist in an insulating material, which could allow for highly efficient electrical control of magnetic order.

Finite Temperature Magnetism in the Triangular Lattice Antiferromagnet KErTe2

Abstract After the discovery of the ARECh2 (A = alkali or monovalent ions, RE = rare-earth, Ch = chalcogen) triangular lattice quantum spin liquid (QSL) family, a series of its oxide, sulfide, and selenide counterparts has been consistently reported and extensively investigated. While KErTe2 represents the initial synthesized telluride member, preserving its triangular spin lattice, it was anticipated that the substantial tellurium ions could impart more pronounced magnetic attributes and electronic structures to this material class. This study delves into the magnetism of KErTe2 at finite temperatures through magnetization and electron spin resonance (ESR) measurements. Based on the angular momentum J ^ after spin-orbit coupling (SOC) and symmetry analysis, we obtain the magnetic effective Hamiltonian to describe the magnetism of Er3+ in R 3 ¯ m space group. Applying the mean-field approximation to the Hamiltonian, we can simulate the magnetization and magnetic heat capacity of KErTe2 in paramagnetic state and determine the crystalline electric field (CEF) parameters and partial exchange interactions. The relatively narrow energy gaps between the CEF ground state and excited states exert a significant influence on the magnetism. For example, small CEF excitations can result in a significant broadening of the ESR linewidth at 2 K. For the fitted exchange interactions, although the values are small, given a large angular momentum J = 15/2 after SOC, they still have a noticeable effect at finite temperatures. Notably, the heat capacity data under different magnetic fields along the c axis direction also roughly match our calculated results, further validating the reliability of our analytical approach. These derived parameters serve as crucial tools for future investigations into the ground state magnetism of KErTe2. The findings presented herein lay a foundation for exploration of the intricate magnetism within the triangular-lattice delafossite family.

Anomalous Nernst effect in the noncollinear antiferromagnet Mn5Si3

Investigating the off-diagonal components of the conductivity and thermoelectric tensor of materials hosting complex antiferromagnetic structures has become a viable method to reveal the effects of topology and chirality on the electronic transport in these systems. In this respect, Mn5Si3 is an interesting metallic compound that exhibits several antiferromagnetic phases below 100 K with different collinear and noncollinear arrangements of Mn magnetic moments determined from neutron scattering. Previous electronic transport measurements have shown that the transitions between the various phases give rise to large changes of the anomalous Hall effect. Here, we report measurements of the anomalous Nernst effect of Mn5Si3 single crystals that also show clear transitions between the different magnetic phases. In the noncollinear phase, we observe an unusual sign change of the zero-field Nernst signal with a concomitant decrease of the Hall signal and a gradual reduction of the remanent magnetization. Furthermore, a symmetry analysis of the proposed magnetic structures shows that both effects should actually vanish. These results indicate a symmetry-breaking modification of the magnetic state with a rearrangement of the magnetic moments at low temperatures, thus questioning the previously reported models for the noncollinear magnetic structure obtained from neutron scattering.

General Theory for Longitudinal Nonreciprocal Charge Transport.

The longitudinal nonreciprocal charge transport (NCT) in crystalline materials is a highly nontrivial phenomenon, motivating the design of next generation two-terminal rectification devices (e.g., semiconductor diodes beyond PN junctions). The practical application of such devices is built upon crystalline materials whose longitudinal NCT occurs at room temperature and under low magnetic field. However, materials of this type are rather rare and elusive, and theory guiding the discovery of these materials is lacking. Here, we develop such a theory within the framework of semiclassical Boltzmann transport theory. By symmetry analysis, we classify the complete 122magnetic point groups with respect to the longitudinal NCT phenomenon. The symmetry-adapted Hamiltonian analysis further uncovers a previously overlooked mechanism for this phenomenon. Our theory guides the first-principles prediction of longitudinal NCT in multiferroic ϵ-Fe_{2}O_{3} semiconductor that possibly occurs at room temperature, without the application of external magnetic field. These findings advance our fundamental understandings of longitudinal NCT in crystalline materials, and aid the corresponding materials discoveries.