Pub Date : 2024-09-12DOI: 10.1209/0295-5075/ad7286
Jiangpeng Song, Junbo Li and Zan Du
The magnetic semimetal SrMnSb2 contains a nonsymmorphic crystal symmetry that could protect Dirac crossings, offering the coexistence of a quasi-two-dimensional characteristic, magnetic order and nontrivial topology in bulk single crystals. Here, we report the evolution of Fermi surfaces by probing quantum oscillations in the LaxSr1-xMnSb2 single crystals. Hall measurements reveal that the conduction process changes from a hole-dominated multiband nature to a single hole-band nature after La doping. Compared with parent-SrMnSb2, the Fermi surface corresponding to Fα is slightly enlarged and the small Fermi surface corresponding to Fγ appears with a tunable feature in La-doped crystals. The topological semimetal candidates LaxSr1-xMnSb2 provide a fine-tuning platform for potential applications in the future.
磁性半金属 SrMnSb2 包含一种非非晶态晶体对称性，可以保护狄拉克交叉，从而在块状单晶中实现准二维特性、磁秩序和非三维拓扑的共存。在这里，我们通过探测 LaxSr1-xMnSb2 单晶中的量子振荡，报告了费米面的演变。霍尔测量结果表明，掺入 La 后，传导过程从空穴主导的多波段性质转变为单个空穴波段性质。与母体-SrMnSb2 相比，掺 La 晶体中与 Fα 相对应的费米面略有扩大，而与 Fγ 相对应的小费米面则出现了可调谐的特征。拓扑半金属候选物 LaxSr1-xMnSb2 为未来的潜在应用提供了一个微调平台。
{"title":"Tunable quantum transport in topological semimetal candidates LaxSr1-xMnSb2","authors":"Jiangpeng Song, Junbo Li and Zan Du","doi":"10.1209/0295-5075/ad7286","DOIUrl":"https://doi.org/10.1209/0295-5075/ad7286","url":null,"abstract":"The magnetic semimetal SrMnSb2 contains a nonsymmorphic crystal symmetry that could protect Dirac crossings, offering the coexistence of a quasi-two-dimensional characteristic, magnetic order and nontrivial topology in bulk single crystals. Here, we report the evolution of Fermi surfaces by probing quantum oscillations in the LaxSr1-xMnSb2 single crystals. Hall measurements reveal that the conduction process changes from a hole-dominated multiband nature to a single hole-band nature after La doping. Compared with parent-SrMnSb2, the Fermi surface corresponding to Fα is slightly enlarged and the small Fermi surface corresponding to Fγ appears with a tunable feature in La-doped crystals. The topological semimetal candidates LaxSr1-xMnSb2 provide a fine-tuning platform for potential applications in the future.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"15 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1209/0295-5075/ad7317
V. Damljanović
In two-dimensional (2D), non-magnetic materials, a single Dirac cone at high-symmetry point (HSP) of the Brillouin zone (BZ), akin to the one in graphenes’ band structure, cannot appear as the only quasiparticle at the Fermi level. Here we found two layer groups with time-reversal symmetry, among all possible both without and with spin-orbit coupling, that host one Dirac cone at HSP and we show which additional dispersions appear: a pair of Dirac lines on opposite BZ edges and a pair of Dirac cones that can be moved but not removed by symmetry preserving perturbations, on the other two BZ edges. We illustrate our theory by a tight-binding band structure and discuss real 2D materials that belong to one of the two symmetry groups. Finally, we single out smaller or bigger discrepancies among the published papers on the same or related topic.
{"title":"Non-magnetic layers with a single symmetry-protected Dirac cone: Which additional dispersions must appear?","authors":"V. Damljanović","doi":"10.1209/0295-5075/ad7317","DOIUrl":"https://doi.org/10.1209/0295-5075/ad7317","url":null,"abstract":"In two-dimensional (2D), non-magnetic materials, a single Dirac cone at high-symmetry point (HSP) of the Brillouin zone (BZ), akin to the one in graphenes’ band structure, cannot appear as the only quasiparticle at the Fermi level. Here we found two layer groups with time-reversal symmetry, among all possible both without and with spin-orbit coupling, that host one Dirac cone at HSP and we show which additional dispersions appear: a pair of Dirac lines on opposite BZ edges and a pair of Dirac cones that can be moved but not removed by symmetry preserving perturbations, on the other two BZ edges. We illustrate our theory by a tight-binding band structure and discuss real 2D materials that belong to one of the two symmetry groups. Finally, we single out smaller or bigger discrepancies among the published papers on the same or related topic.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"81 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1209/0295-5075/ad73fe
D. E. Zenkhri, A. Benkrane and M. T. Meftah
Gaunt factors are fundamental in describing the interaction of free electrons with photons, playing a crucial role in astrophysical processes such as radiation transport and emission spectra. Traditional methods for computing Gaunt factors involve complex integrations and intricate mathematical formulations, often being computationally expensive and time-consuming. This study explores an alternative approach using machine learning models to predict free-free Gaunt factors. Three models were employed: Artificial Neural Network (ANN), Support Vector Regression (SVR), and Gradient Boosting Regression (GBR). The obtained results demonstrate high performance, with R2 scores ranging from 0.98 to 0.99, indicating the potential of machine learning models to accurately predict Gaunt factors.
{"title":"Total free-free Gaunt factors prediction using machine learning models","authors":"D. E. Zenkhri, A. Benkrane and M. T. Meftah","doi":"10.1209/0295-5075/ad73fe","DOIUrl":"https://doi.org/10.1209/0295-5075/ad73fe","url":null,"abstract":"Gaunt factors are fundamental in describing the interaction of free electrons with photons, playing a crucial role in astrophysical processes such as radiation transport and emission spectra. Traditional methods for computing Gaunt factors involve complex integrations and intricate mathematical formulations, often being computationally expensive and time-consuming. This study explores an alternative approach using machine learning models to predict free-free Gaunt factors. Three models were employed: Artificial Neural Network (ANN), Support Vector Regression (SVR), and Gradient Boosting Regression (GBR). The obtained results demonstrate high performance, with R2 scores ranging from 0.98 to 0.99, indicating the potential of machine learning models to accurately predict Gaunt factors.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"52 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142258468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-04DOI: 10.1209/0295-5075/ad7285
Dmitry A. Smirnov
The concept of dynamical causal effect (DCE) which unites numerous causality quantifiers for processes in dynamical systems (DS) as measures of X-responses to some Y-variations is generalised through updating the definition of the factors constituting those variations. Along with initial states and governing parameters, external driving (noise) realisations are included and all three factors are represented with their probability distributions. Three basic levels of DCEs are introduced based on their resolution with respect to each factor: low (three factors resolved), medium (two factors), and high (one factor). It is shown that i) a directional coupling with zero transfer entropy (a medium-level DCE) may be strong in terms of its low-level DCEs; ii) DCEs of the same level may be small or large depending on their Y-variations, e.g., a coupling which induces synronisation is both weak and strong according to different medium-level DCEs; iii) high-level DCEs allow comparison of couplings from different sources which may be inaccessible via medium-level DCEs. The generalised DCE concept applies to arbitrary DS including deterministic (driven) DS and random DS with any kind of noise.
动态因果效应（DCE）的概念将动态系统（DS）中众多过程的因果关系量化指标统一为对某些 Y 变化的 X 反应的度量，通过更新构成这些变化的因素的定义，DCE 的概念得到了推广。除了初始状态和控制参数外，还包括外部驱动（噪声）现实，所有三个因素都用其概率分布来表示。根据每个因素的分辨率，引入了三个基本级别的 DCE：低（三个因素分辨率）、中（两个因素）和高（一个因素）。研究表明：i) 从低级 DCEs 的角度看，转移熵为零的定向耦合（中级 DCE）可能很强；ii) 同一级别的 DCEs 可能很小，也可能很大，这取决于它们的 Y 变量，例如，根据不同的中级 DCEs，引起同步化的耦合既弱又强；iii) 高级 DCEs 可以比较不同来源的耦合，而中级 DCEs 可能无法比较这些耦合。广义 DCE 概念适用于任意 DS，包括确定性（驱动）DS 和带有任何噪声的随机 DS。
{"title":"“Causometry” of processes in arbitrary dynamical systems: Three levels of directional coupling quantifiers","authors":"Dmitry A. Smirnov","doi":"10.1209/0295-5075/ad7285","DOIUrl":"https://doi.org/10.1209/0295-5075/ad7285","url":null,"abstract":"The concept of dynamical causal effect (DCE) which unites numerous causality quantifiers for processes in dynamical systems (DS) as measures of X-responses to some Y-variations is generalised through updating the definition of the factors constituting those variations. Along with initial states and governing parameters, external driving (noise) realisations are included and all three factors are represented with their probability distributions. Three basic levels of DCEs are introduced based on their resolution with respect to each factor: low (three factors resolved), medium (two factors), and high (one factor). It is shown that i) a directional coupling with zero transfer entropy (a medium-level DCE) may be strong in terms of its low-level DCEs; ii) DCEs of the same level may be small or large depending on their Y-variations, e.g., a coupling which induces synronisation is both weak and strong according to different medium-level DCEs; iii) high-level DCEs allow comparison of couplings from different sources which may be inaccessible via medium-level DCEs. The generalised DCE concept applies to arbitrary DS including deterministic (driven) DS and random DS with any kind of noise.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"6 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-04DOI: 10.1209/0295-5075/ad7287
G. F. Quinteiro Rosen and P. I. Tamborenea
Fueled by the rapid pace of technological advancements, the convergence of ideas from optics and solid-state physics is yielding valuable insights into the fundamental principles governing interactions between light and matter at the nanoscale, as well as paving the way for future technologies. In this review, we explore a burgeoning avenue that investigates the synergy between plasmonics and optical vortex concepts. The excitation of plasmon modes with phase dislocations, occasionally referred to as plasmonic vortices, has revealed novel facets of physics. One particularly promising expansion of this field pertains to the manipulation of nearby nanostructures. Consequently, we provide commentary on the associated research, which offers innovative solutions to a variety of technological challenges.
{"title":"Prospects for the use of plasmonic vortices to control nanosystems","authors":"G. F. Quinteiro Rosen and P. I. Tamborenea","doi":"10.1209/0295-5075/ad7287","DOIUrl":"https://doi.org/10.1209/0295-5075/ad7287","url":null,"abstract":"Fueled by the rapid pace of technological advancements, the convergence of ideas from optics and solid-state physics is yielding valuable insights into the fundamental principles governing interactions between light and matter at the nanoscale, as well as paving the way for future technologies. In this review, we explore a burgeoning avenue that investigates the synergy between plasmonics and optical vortex concepts. The excitation of plasmon modes with phase dislocations, occasionally referred to as plasmonic vortices, has revealed novel facets of physics. One particularly promising expansion of this field pertains to the manipulation of nearby nanostructures. Consequently, we provide commentary on the associated research, which offers innovative solutions to a variety of technological challenges.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"86 1 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-03DOI: 10.1209/0295-5075/ad6e16
Tingmei Li, Hong-Xia Li, Yu-Hui Chen and Xiangdong Zhang
The spontaneous emergence of temporal structures challenges the conventional understanding that systems governed by time-invariant laws remain unchanged over time. Recent experiments have observed this time translation symmetry breaking in quantum atomic systems that either exhibit strong atom-atom interactions or have low dissipation rates. While current theoretical frameworks reveal the importance of strong atom-atom interactions, they fall short in explaining this phenomenon observed in low-dissipation atomic systems. Here, we present a theoretical study on the spontaneous breaking of time translation symmetry in materials with low dissipation rates. By constructing phase diagrams for a system of four-level atoms driven by a continuous-wave optical field, we identify the essential requirements for self-sustained temporal motions. These include a driven open system, nonlinear interactions, and sufficient degrees of freedom that facilitate competing processes. Our findings contribute to a better understanding of the emergence of spontaneous time translation symmetry breaking in these materials.
{"title":"Spontaneous emergence of temporal structures in a continuously driven many-body system","authors":"Tingmei Li, Hong-Xia Li, Yu-Hui Chen and Xiangdong Zhang","doi":"10.1209/0295-5075/ad6e16","DOIUrl":"https://doi.org/10.1209/0295-5075/ad6e16","url":null,"abstract":"The spontaneous emergence of temporal structures challenges the conventional understanding that systems governed by time-invariant laws remain unchanged over time. Recent experiments have observed this time translation symmetry breaking in quantum atomic systems that either exhibit strong atom-atom interactions or have low dissipation rates. While current theoretical frameworks reveal the importance of strong atom-atom interactions, they fall short in explaining this phenomenon observed in low-dissipation atomic systems. Here, we present a theoretical study on the spontaneous breaking of time translation symmetry in materials with low dissipation rates. By constructing phase diagrams for a system of four-level atoms driven by a continuous-wave optical field, we identify the essential requirements for self-sustained temporal motions. These include a driven open system, nonlinear interactions, and sufficient degrees of freedom that facilitate competing processes. Our findings contribute to a better understanding of the emergence of spontaneous time translation symmetry breaking in these materials.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"55 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-28DOI: 10.1209/0295-5075/ad6f3e
Ting Liu, Hongwei Liu and Jingwei Yin
The increase of the concentrated density of wave energy is conducive to improving the generation efficiency of wave power generation. Interface states induced in the heterostructure channels can be applied to concentrate the surface water wave. The optimal designs of heterostructure channels can be found through the topology optimization based on the multiple population genetic algorithm to induce a topological interface state with high transmission at the desired frequency. The introduction of the topological interface state effectively and steadily increases the wave energy density in a certain space and improves the robustness and the localization of the water wave concentrator. This topology optimization method provides a design scheme for the wave energy concentrator in the field of ocean engineering.
{"title":"Heterostructure channel designs for the topological interface state of surface water waves using topology optimization","authors":"Ting Liu, Hongwei Liu and Jingwei Yin","doi":"10.1209/0295-5075/ad6f3e","DOIUrl":"https://doi.org/10.1209/0295-5075/ad6f3e","url":null,"abstract":"The increase of the concentrated density of wave energy is conducive to improving the generation efficiency of wave power generation. Interface states induced in the heterostructure channels can be applied to concentrate the surface water wave. The optimal designs of heterostructure channels can be found through the topology optimization based on the multiple population genetic algorithm to induce a topological interface state with high transmission at the desired frequency. The introduction of the topological interface state effectively and steadily increases the wave energy density in a certain space and improves the robustness and the localization of the water wave concentrator. This topology optimization method provides a design scheme for the wave energy concentrator in the field of ocean engineering.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"3 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-28DOI: 10.1209/0295-5075/ad6eb5
Lingxiao Long and Yunguo Jiang
In theory, the resonance scattering structure is triggered by the so-called delocalized modes trapped between the pair. The frequencies and configurations of such modes depend on the half-separation a, which can be derived from the Schrödinger-like equation. We propose to use the boundary conditions to connect the half-localized and delocalized modes, and use boundary approximation (BA) to solve the spectrum analytically. In detail, we derive the explicit form of frequencies, configurations and spectral wall locations of the delocalized modes. We test the analytical prediction with the numerical simulation of the Schrödinger-like equation, and obtain astonishing agreement between them at the long separation regime.
{"title":"Solving the spectral problem via the boundary approximation in theory","authors":"Lingxiao Long and Yunguo Jiang","doi":"10.1209/0295-5075/ad6eb5","DOIUrl":"https://doi.org/10.1209/0295-5075/ad6eb5","url":null,"abstract":"In theory, the resonance scattering structure is triggered by the so-called delocalized modes trapped between the pair. The frequencies and configurations of such modes depend on the half-separation a, which can be derived from the Schrödinger-like equation. We propose to use the boundary conditions to connect the half-localized and delocalized modes, and use boundary approximation (BA) to solve the spectrum analytically. In detail, we derive the explicit form of frequencies, configurations and spectral wall locations of the delocalized modes. We test the analytical prediction with the numerical simulation of the Schrödinger-like equation, and obtain astonishing agreement between them at the long separation regime.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"21 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-27DOI: 10.1209/0295-5075/ad6bbc
Iñigo Robredo, Niels B. M. Schröter, Claudia Felser, Jennifer Cano, Barry Bradlyn and Maia G. Vergniory
The discovery of topological semimetals with multifold band crossings has opened up a new and exciting frontier in the field of topological physics. These materials exhibit large Chern numbers, leading to long double Fermi arcs on their surfaces, which are protected by either crystal symmetries or topological order. The impact of these multifold crossings extends beyond surface science, as they are not constrained by the Poincar classification of quasiparticles and only need to respect the crystal symmetry of one of the 1651 magnetic space groups. Consequently, we observe the emergence of free fermionic excitations in solid-state systems that have no high-energy counterparts, protected by non-symmorphic symmetries. In this work, we review the recent theoretical and experimental progress made in the field of multifold topological semimetals. We begin with the theoretical prediction of the so-called multifold fermions and discuss the subsequent discoveries of chiral and magnetic topological semimetals. Several experiments that have realized chiral semimetals in spectroscopic measurements are described, and we discuss the future prospects of this field. These exciting developments have the potential to deepen our understanding of the fundamental properties of quantum matter and inspire new technological applications in the future.
{"title":"Multifold topological semimetals","authors":"Iñigo Robredo, Niels B. M. Schröter, Claudia Felser, Jennifer Cano, Barry Bradlyn and Maia G. Vergniory","doi":"10.1209/0295-5075/ad6bbc","DOIUrl":"https://doi.org/10.1209/0295-5075/ad6bbc","url":null,"abstract":"The discovery of topological semimetals with multifold band crossings has opened up a new and exciting frontier in the field of topological physics. These materials exhibit large Chern numbers, leading to long double Fermi arcs on their surfaces, which are protected by either crystal symmetries or topological order. The impact of these multifold crossings extends beyond surface science, as they are not constrained by the Poincar classification of quasiparticles and only need to respect the crystal symmetry of one of the 1651 magnetic space groups. Consequently, we observe the emergence of free fermionic excitations in solid-state systems that have no high-energy counterparts, protected by non-symmorphic symmetries. In this work, we review the recent theoretical and experimental progress made in the field of multifold topological semimetals. We begin with the theoretical prediction of the so-called multifold fermions and discuss the subsequent discoveries of chiral and magnetic topological semimetals. Several experiments that have realized chiral semimetals in spectroscopic measurements are described, and we discuss the future prospects of this field. These exciting developments have the potential to deepen our understanding of the fundamental properties of quantum matter and inspire new technological applications in the future.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"48 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1209/0295-5075/ad6bba
Nannan Shi, Han Liu and Liutao Zhao
Seismic metamaterials (SMs) possess bandgap characteristics, enabling effective attenuation of seismic waves within a specific frequency range. However, small-sized SMs typically struggle to achieve a wide low-frequency bandgap. This paper proposes four types of SMs. The dispersion curves of these models were analyzed, and their vibration modes were studied to elucidate the bandgap mechanism. To investigate the influence of structural parameters on the bandgap, geometric variables are analyzed. Subsequently, the spectrum and acceleration time history curves of Lamb waves in a finite SM system are analyzed to verify the bandgap's authenticity. The designed structure exhibits a bandgap ranging from 1.24 Hz to 16.86 Hz, with a relative bandwidth as high as 172.6% and over 96% maximum vibration displacement attenuation of the El Centro seismic wave. The designed SMs effectively cover the 2 Hz seismic peak spectrum that leads to structural damage. They possess ideal relative bandwidth and excellent isolation performance, further advancing the engineering application of SMs.
地震超材料（SM）具有带隙特性，可在特定频率范围内有效衰减地震波。然而，小尺寸超材料通常难以实现较宽的低频带隙。本文提出了四种 SM。分析了这些模型的频散曲线，并研究了它们的振动模式，以阐明带隙机制。为了研究结构参数对带隙的影响，本文分析了几何变量。随后，分析了有限 SM 系统中 Lamb 波的频谱和加速度时间历史曲线，以验证带隙的真实性。设计结构的带隙范围为 1.24 Hz 至 16.86 Hz，相对带宽高达 172.6%，对 El Centro 地震波的最大振动位移衰减超过 96%。所设计的 SM 能有效覆盖导致结构损坏的 2 Hz 地震峰值频谱。它们具有理想的相对带宽和优异的隔离性能，进一步推动了 SM 的工程应用。
{"title":"Novel small-size seismic metamaterial with ultra-low frequency bandgap for Lamb waves","authors":"Nannan Shi, Han Liu and Liutao Zhao","doi":"10.1209/0295-5075/ad6bba","DOIUrl":"https://doi.org/10.1209/0295-5075/ad6bba","url":null,"abstract":"Seismic metamaterials (SMs) possess bandgap characteristics, enabling effective attenuation of seismic waves within a specific frequency range. However, small-sized SMs typically struggle to achieve a wide low-frequency bandgap. This paper proposes four types of SMs. The dispersion curves of these models were analyzed, and their vibration modes were studied to elucidate the bandgap mechanism. To investigate the influence of structural parameters on the bandgap, geometric variables are analyzed. Subsequently, the spectrum and acceleration time history curves of Lamb waves in a finite SM system are analyzed to verify the bandgap's authenticity. The designed structure exhibits a bandgap ranging from 1.24 Hz to 16.86 Hz, with a relative bandwidth as high as 172.6% and over 96% maximum vibration displacement attenuation of the El Centro seismic wave. The designed SMs effectively cover the 2 Hz seismic peak spectrum that leads to structural damage. They possess ideal relative bandwidth and excellent isolation performance, further advancing the engineering application of SMs.","PeriodicalId":11738,"journal":{"name":"EPL","volume":"55 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142209956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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