Pub Date : 2024-11-15DOI: 10.1016/j.physleta.2024.130060
H.W.A. Riaz , J. Lin , J. Wang
In this paper, we present an extended semi-discrete matrix coupled dispersionless system, building on the framework explored in [Appl. Math. Lett. 158 (2024) 109217]. We propose a Lax pair and employ the Darboux transformation to construct explicit solutions. These solutions reveal diverse phenomena, including periodic patterns, breathers, and rogue waves. Notably, the extended system exhibits intricate interactions between bright and dark solitons and between bright solitons and rogue waves. Furthermore, we provide a numerical experiment for the reduced semi-discrete coupled dispersionless equations to demonstrate the effectiveness of the developed method.
本文以[Appl. Math. Lett. 158 (2024) 109217]中探索的框架为基础，提出了一个扩展的半离散矩阵耦合无色散系统。我们提出了一个拉克斯对，并利用达尔布克斯变换构建了显式解。这些解揭示了各种现象，包括周期模式、呼吸波和流氓波。值得注意的是，扩展系统在亮孤子和暗孤子之间以及亮孤子和流氓波之间表现出错综复杂的相互作用。此外，我们还提供了还原半离散耦合无分散方程的数值实验，以证明所开发方法的有效性。
{"title":"On an extended semi-discrete matrix coupled dispersionless system: Darboux transformation and explicit solutions","authors":"H.W.A. Riaz , J. Lin , J. Wang","doi":"10.1016/j.physleta.2024.130060","DOIUrl":"10.1016/j.physleta.2024.130060","url":null,"abstract":"<div><div>In this paper, we present an extended semi-discrete matrix coupled dispersionless system, building on the framework explored in [Appl. Math. Lett. 158 (2024) 109217]. We propose a Lax pair and employ the Darboux transformation to construct explicit solutions. These solutions reveal diverse phenomena, including periodic patterns, breathers, and rogue waves. Notably, the extended system exhibits intricate interactions between bright and dark solitons and between bright solitons and rogue waves. Furthermore, we provide a numerical experiment for the reduced semi-discrete coupled dispersionless equations to demonstrate the effectiveness of the developed method.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130060"},"PeriodicalIF":2.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-14DOI: 10.1016/j.physleta.2024.130058
Qinghan Xue, Jiaqi Song, Xingqin Qi
Seldom research considers both the “speed” of information spreading and also the dynamic way of selecting seeds, i.e., choosing node step by step instead of one-time selecting. Graph burning model is used here to meet these requirements of information spreading, whose objective is to find a shortest sequence of nodes and activate them sequentially so that the network is eventually activated completely. This problem has been proven to be NP-Hard. However, few heuristic or approximate algorithms exist, even for trees. Thus, in this paper we propose a novel tree burning algorithm called DASH, where the node with both a strong burning capacity and large spacing to the existing activated nodes is selected as a new seed sequentially. This DASH algorithm is implemented and compared with existing algorithms on 20 spanning subtrees of real networks and 15 randomly generated trees, and the experimental results demonstrate that DASH performs better.
{"title":"DASH: A novel method for dynamically selecting key nodes to spread information rapidly under the graph burning model","authors":"Qinghan Xue, Jiaqi Song, Xingqin Qi","doi":"10.1016/j.physleta.2024.130058","DOIUrl":"10.1016/j.physleta.2024.130058","url":null,"abstract":"<div><div>Seldom research considers both the “speed” of information spreading and also the dynamic way of selecting seeds, i.e., choosing node step by step instead of one-time selecting. Graph burning model is used here to meet these requirements of information spreading, whose objective is to find a shortest sequence of nodes and activate them sequentially so that the network is eventually activated completely. This problem has been proven to be NP-Hard. However, few heuristic or approximate algorithms exist, even for trees. Thus, in this paper we propose a novel tree burning algorithm called DASH, where the node with both a strong burning capacity and large spacing to the existing activated nodes is selected as a new seed sequentially. This DASH algorithm is implemented and compared with existing algorithms on 20 spanning subtrees of real networks and 15 randomly generated trees, and the experimental results demonstrate that DASH performs better.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130058"},"PeriodicalIF":2.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
The present study investigates the structural, electronic, thermal, and optical properties of a novel two-dimensional Al2Te3 using GGA and HSE06 functional in the framework of density functional theory. The formation energy, the phonon dispersion, and AIMD calculations confirm the structural, dynamical, and thermal stability of Al2Te3, respectively. The electronic band structure and partial density of states indicate the semiconducting characteristics of 2D Al2Te3 with band gap values of 1.92 eV (GGA) and 2.78 eV (HSE06). The thermal properties of Al2Te3 reveal a high heat capacity due to a very high phonon density of states. This property signifies the material's growing ability to store thermal energy. Thus the entropy demonstrates a continuous increase with temperature, adhering to the second law of thermodynamics. The analysis of optical properties of Al2Te3 demonstrates strong light interaction in the ultraviolet, UV, region, and the optical band gap is found to be larger than the electronic band gap for both GGA and HSE06 functional due to indirect behavior of the band gap. Furthermore, the static dielectric function, refractive index, and optical conductivity are found to be smaller in the case of HSE06 compared to the GGA which may be due to reduced transition probability, and less screening effects including in the HSE06 functional. These findings offer valuable insights into the potential applications of Al2Te3 in various fields, including thermal energy storage and optoelectronics.
{"title":"High thermal energy storage of the two-dimensional Al2Te3 semiconductor: DFT study of stability, electronic, phonon, thermal, and optical properties based on GGA and HSE06","authors":"Nzar Rauf Abdullah , Yousif Hussein Azeez , Bashdar Rahman Pirot , Vidar Gudmundsson","doi":"10.1016/j.physleta.2024.130052","DOIUrl":"10.1016/j.physleta.2024.130052","url":null,"abstract":"<div><div>The present study investigates the structural, electronic, thermal, and optical properties of a novel two-dimensional Al<sub>2</sub>Te<sub>3</sub> using GGA and HSE06 functional in the framework of density functional theory. The formation energy, the phonon dispersion, and AIMD calculations confirm the structural, dynamical, and thermal stability of Al<sub>2</sub>Te<sub>3</sub>, respectively. The electronic band structure and partial density of states indicate the semiconducting characteristics of 2D Al<sub>2</sub>Te<sub>3</sub> with band gap values of 1.92 eV (GGA) and 2.78 eV (HSE06). The thermal properties of Al<sub>2</sub>Te<sub>3</sub> reveal a high heat capacity due to a very high phonon density of states. This property signifies the material's growing ability to store thermal energy. Thus the entropy demonstrates a continuous increase with temperature, adhering to the second law of thermodynamics. The analysis of optical properties of Al<sub>2</sub>Te<sub>3</sub> demonstrates strong light interaction in the ultraviolet, UV, region, and the optical band gap is found to be larger than the electronic band gap for both GGA and HSE06 functional due to indirect behavior of the band gap. Furthermore, the static dielectric function, refractive index, and optical conductivity are found to be smaller in the case of HSE06 compared to the GGA which may be due to reduced transition probability, and less screening effects including in the HSE06 functional. These findings offer valuable insights into the potential applications of Al<sub>2</sub>Te<sub>3</sub> in various fields, including thermal energy storage and optoelectronics.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130052"},"PeriodicalIF":2.3,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-12DOI: 10.1016/j.physleta.2024.130055
Si-Si Wu , Qian Liu , Dan Wu , Gui-Ping Tang , Zhi-Qiang Fan , Fang Xie
We use first-principles method to investigate the electronic and optical properties of blue phosphorene (BP) adsorbed by alkali metal atoms. Alkali metal atoms form bonds with adjacent three phosphorus atoms at the hollow (H) and valley (V) sites, resulting in higher adsorption energies than that at the Top (T) site. Alkali metal atoms adsorbed on the H, V and T sits all transfer charges to BP, forcing the intrinsic BP energy band to shift towards negative energy, resulting in its transition from semiconductor to metal. The BP adsorbed by Li atoms at the H and V sits exhibit excellent optical properties. The light absorption coefficient spectrum shows a clear absorption peak in the infrared region, and the absorption width covers the entire near-infrared light. In addition, the coefficient and width of the absorption peak will further increase with the rise of the number of adsorbed Li atoms.
我们采用第一原理方法研究了被碱金属原子吸附的蓝色磷烯（BP）的电子和光学特性。碱金属原子在空位（H）和谷位（V）上与相邻的三个磷原子形成键合，导致吸附能高于在顶位（T）上的吸附能。吸附在 H、V 和 T 位点上的碱金属原子都会将电荷转移到 BP 上，从而迫使 BP 的固有能带向负能量方向移动，导致其从半导体转变为金属。被锂原子吸附在 H 位和 V 位的 BP 具有优异的光学特性。光吸收系数光谱在红外区域显示出明显的吸收峰，吸收宽度覆盖整个近红外光。此外，随着吸附锂原子数量的增加，吸收峰的系数和宽度也会进一步增大。
{"title":"Tunable electronic structure and enhanced optical properties of blue phosphorene via adsorption of alkali metal atoms","authors":"Si-Si Wu , Qian Liu , Dan Wu , Gui-Ping Tang , Zhi-Qiang Fan , Fang Xie","doi":"10.1016/j.physleta.2024.130055","DOIUrl":"10.1016/j.physleta.2024.130055","url":null,"abstract":"<div><div>We use first-principles method to investigate the electronic and optical properties of blue phosphorene (BP) adsorbed by alkali metal atoms. Alkali metal atoms form bonds with adjacent three phosphorus atoms at the hollow (H) and valley (V) sites, resulting in higher adsorption energies than that at the Top (T) site. Alkali metal atoms adsorbed on the H, V and T sits all transfer charges to BP, forcing the intrinsic BP energy band to shift towards negative energy, resulting in its transition from semiconductor to metal. The BP adsorbed by Li atoms at the H and V sits exhibit excellent optical properties. The light absorption coefficient spectrum shows a clear absorption peak in the infrared region, and the absorption width covers the entire near-infrared light. In addition, the coefficient and width of the absorption peak will further increase with the rise of the number of adsorbed Li atoms.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130055"},"PeriodicalIF":2.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-12DOI: 10.1016/j.physleta.2024.130059
Kun Li , Zhiyu Chen
Whether crowd cooperation behaviors bring benefit for pedestrians evacuating under panic conditions is still an open issue. Motivated by this, an improved cellular automaton model based on evolutionary game theory is proposed, focused on the impact of panic thresholds on evacuation efficiency in different emergency scenarios. Three distinct game paradigms, namely Snowdrift, Stag Hunt and Prisoner's Dilemma games are used to characterize these scenarios where pedestrian evacuation processes. Interestingly, in Snowdrift and Stag Hunt games, pedestrians tend to choose cooperation, therefore queuing orderly; whereas in the Prisoner's Dilemma, they are more likely to defect, exhibiting extremely aggression. The study also explores the impact of varying levels of cooperative behavior and panic thresholds on evacuation efficiency under different conditions. Overall, higher panic thresholds promote evacuation efficiency. The findings provide new insights into pedestrian evacuation behavior and hold significant implications for improving evacuation efficiency and management in real-life scenarios.
{"title":"Emergency evacuation dynamics based on evolutionary game theory","authors":"Kun Li , Zhiyu Chen","doi":"10.1016/j.physleta.2024.130059","DOIUrl":"10.1016/j.physleta.2024.130059","url":null,"abstract":"<div><div>Whether crowd cooperation behaviors bring benefit for pedestrians evacuating under panic conditions is still an open issue. Motivated by this, an improved cellular automaton model based on evolutionary game theory is proposed, focused on the impact of panic thresholds on evacuation efficiency in different emergency scenarios. Three distinct game paradigms, namely Snowdrift, Stag Hunt and Prisoner's Dilemma games are used to characterize these scenarios where pedestrian evacuation processes. Interestingly, in Snowdrift and Stag Hunt games, pedestrians tend to choose cooperation, therefore queuing orderly; whereas in the Prisoner's Dilemma, they are more likely to defect, exhibiting extremely aggression. The study also explores the impact of varying levels of cooperative behavior and panic thresholds on evacuation efficiency under different conditions. Overall, higher panic thresholds promote evacuation efficiency. The findings provide new insights into pedestrian evacuation behavior and hold significant implications for improving evacuation efficiency and management in real-life scenarios.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130059"},"PeriodicalIF":2.3,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-10DOI: 10.1016/j.physleta.2024.130056
Cuncheng Weng
In acousto-optic interaction, it is widely known that the frequency and phase of light are ultrasound-shifted in both transparent and turbid media, and furthermore the phase is also ultrasound-modulated in turbid media. However, it has been unclear whether there is an inherent relationship between the ultrasound-caused shifts in optical frequency and phase and the modulation of optical phase in turbid media. In the letter, we reveal that the ultrasound-caused shifts in optical frequency and phase depend on the modulation of optical phase in acousto-optic interaction of turbid media. Additionally, the intensity of frequency-shifted light is related to the modulation of optical phase. Then, with the increase of the modulation amplitude of optical phase, the phase-modulated light comprises relatively more light waves with higher frequency shifts. At last, the conclusions are confirmed by heterodyne experiments.
{"title":"Dependence of the ultrasound-caused shifts in optical frequency and phase and the modulation of optical phase in acousto-optic interaction of turbid media","authors":"Cuncheng Weng","doi":"10.1016/j.physleta.2024.130056","DOIUrl":"10.1016/j.physleta.2024.130056","url":null,"abstract":"<div><div>In acousto-optic interaction, it is widely known that the frequency and phase of light are ultrasound-shifted in both transparent and turbid media, and furthermore the phase is also ultrasound-modulated in turbid media. However, it has been unclear whether there is an inherent relationship between the ultrasound-caused shifts in optical frequency and phase and the modulation of optical phase in turbid media. In the letter, we reveal that the ultrasound-caused shifts in optical frequency and phase depend on the modulation of optical phase in acousto-optic interaction of turbid media. Additionally, the intensity of frequency-shifted light is related to the modulation of optical phase. Then, with the increase of the modulation amplitude of optical phase, the phase-modulated light comprises relatively more light waves with higher frequency shifts. At last, the conclusions are confirmed by heterodyne experiments.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130056"},"PeriodicalIF":2.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-10DOI: 10.1016/j.physleta.2024.130054
Hongchao Shi, Heng Zhu, Bing Tang, Chao Yang
Upon irradiation with high-frequency circularly polarized light, the Heisenberg spin system on a honeycomb lattice develops a next-nearest neighbor Dzyaloshinskii-Moriya interaction (DMI) term, transforming it into a magnonic Floquet topological insulator with intriguing physical properties. In this context, we investigate the many-body interaction effects of Floquet magnons in a laser-irradiated Heisenberg honeycomb ferromagnet featuring DMI under circularly polarized off-resonant light illumination. Our analysis employs the magnon Floquet-Bloch theory and Green's function method. We demonstrate that quantum ferromagnet systems driven periodically by lasers exhibit temperature-driven topological phase transitions due to Floquet magnon-magnon interactions, transitions that are absent when such interactions are neglected. Furthermore, we observe that the critical temperature necessary for reversing the sign of the topological phase gradually increases with elevated light intensity. This study introduces a novel approach to constructing Floquet topological phases in periodically driven quantum magnet systems.
{"title":"Interacting Floquet topological magnons in laser-irradiated Heisenberg honeycomb ferromagnets","authors":"Hongchao Shi, Heng Zhu, Bing Tang, Chao Yang","doi":"10.1016/j.physleta.2024.130054","DOIUrl":"10.1016/j.physleta.2024.130054","url":null,"abstract":"<div><div>Upon irradiation with high-frequency circularly polarized light, the Heisenberg spin system on a honeycomb lattice develops a next-nearest neighbor Dzyaloshinskii-Moriya interaction (DMI) term, transforming it into a magnonic Floquet topological insulator with intriguing physical properties. In this context, we investigate the many-body interaction effects of Floquet magnons in a laser-irradiated Heisenberg honeycomb ferromagnet featuring DMI under circularly polarized off-resonant light illumination. Our analysis employs the magnon Floquet-Bloch theory and Green's function method. We demonstrate that quantum ferromagnet systems driven periodically by lasers exhibit temperature-driven topological phase transitions due to Floquet magnon-magnon interactions, transitions that are absent when such interactions are neglected. Furthermore, we observe that the critical temperature necessary for reversing the sign of the topological phase gradually increases with elevated light intensity. This study introduces a novel approach to constructing Floquet topological phases in periodically driven quantum magnet systems.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130054"},"PeriodicalIF":2.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-10DOI: 10.1016/j.physleta.2024.130053
Yu-Xuan Li , Jun Zhong , Xiang-Jie Xiong , Yong-Qi Ning , Ying Xu , Hui-Ping Zhu , Yu-Qing Zhao , Bo Li
The emergence of two-dimensional (2D) perovskite provides an ideal platform for designing and fabricating microelectronic and optoelectronic devices. Here, we present detailed ab initio calculations to comprehensively explore the layer-dependent optoelectronic and transport properties of the newly synthesized 2D perovskite Cs3Bi2I9. The calculations reveal that the indirect band gap of monolayer, bilayer, and trilayer Cs3Bi2I9 decreases from 2.41 to 2.35 eV The charge carriers of few-layered perovskite Cs3Bi2I9 are dominated by electrons, and the highest electron and hole carrier mobilities are 140 and 62 cm²V⁻¹s⁻¹ along the b axis for bilayer Cs3Bi2I9. Exciton binding energies decrease from 2.48 to 1.19 eV with an increment of layer, and the calculated exciton level drops down into the valence band to generate potential exciton insulator. 2D Cs3Bi2I9 exhibits potential in the field of ultraviolet detection and photoluminescent devices due to large exciton energy and ultraviolet absorption.
二维（2D）包晶石的出现为设计和制造微电子和光电器件提供了一个理想的平台。在此，我们通过详细的 ab initio 计算，全面探讨了新合成的二维包晶 Cs3Bi2I9 的层依赖性光电和传输特性。计算结果表明，单层、双层和三层 Cs3Bi2I9 的间接带隙从 2.41 eV 减小到 2.35 eV。少层包晶 Cs3Bi2I9 的电荷载流子以电子为主，对于双层 Cs3Bi2I9，沿 b 轴最高的电子和空穴载流子迁移率分别为 140 和 62 cm²V-¹s-¹。随着层数的增加，激子结合能从 2.48 eV 下降到 1.19 eV，计算出的激子水平下降到价带，从而产生潜在的激子绝缘体。二维 Cs3Bi2I9 具有较大的激子能量和紫外线吸收能力，因此在紫外线探测和光致发光器件领域具有潜力。
{"title":"Optoelectronic and transport properties of layer-dependent two-dimensional perovskite Cs3Bi2I9","authors":"Yu-Xuan Li , Jun Zhong , Xiang-Jie Xiong , Yong-Qi Ning , Ying Xu , Hui-Ping Zhu , Yu-Qing Zhao , Bo Li","doi":"10.1016/j.physleta.2024.130053","DOIUrl":"10.1016/j.physleta.2024.130053","url":null,"abstract":"<div><div>The emergence of two-dimensional (2D) perovskite provides an ideal platform for designing and fabricating microelectronic and optoelectronic devices. Here, we present detailed ab initio calculations to comprehensively explore the layer-dependent optoelectronic and transport properties of the newly synthesized 2D perovskite Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>. The calculations reveal that the indirect band gap of monolayer, bilayer, and trilayer Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> decreases from 2.41 to 2.35 eV The charge carriers of few-layered perovskite Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> are dominated by electrons, and the highest electron and hole carrier mobilities are 140 and 62 cm²V⁻¹s⁻¹ along the b axis for bilayer Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub>. Exciton binding energies decrease from 2.48 to 1.19 eV with an increment of layer, and the calculated exciton level drops down into the valence band to generate potential exciton insulator. 2D Cs<sub>3</sub>Bi<sub>2</sub>I<sub>9</sub> exhibits potential in the field of ultraviolet detection and photoluminescent devices due to large exciton energy and ultraviolet absorption.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130053"},"PeriodicalIF":2.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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}
Achieving multiple perfect absorptions from ultraviolet (UV) to near-infrared (IR) region is practically important for metamaterial-based efficient harvesting of photons and biosensor. Here, we theoretically demonstrate a triple narrow and broad perfect absorptions (PAs) from visible to UV range in a lifted metamaterial made of aluminum vertical split-ring resonators (Al VSRR) on silica nanostrip /Al mirror. The three simultaneously achieved narrowband and broadband PAs with bandwidth of 283.3 nm, 8.9 nm and 18.2 nm are excited from magnetic plasmon resonance, surface plasmons polariton and plasmon standing wave mode, respectively, which is further explained by the impedance matching theory. The triple-band absorption peaks are further tailored by changing the size of the structure. The group index of the lifted Al VSRR array can reach as large as 2.5 × 103 in the UV range. Moreover, due to the designed metamaterial being lifted with the reduced substrate effect, the figure of merit (FoM*) and sensitivity (S) in the UV range are as high as 1.1 × 106 and 306 nm per refractive index unit (306 nm/RIU), respectively. The proposed lifted metamaterial could have a considerable effect on the development of various UV plasmonic applications, including slow light nanodevices and optical sensor.
{"title":"Triple ultraviolet to visible perfect absorptions of lifted metamaterial for highly sensitive sensing and slow light","authors":"Lili Yu , Jingsheng Jia , Ping Gu , Jing Chen , Chaojun Tang , Zhendong Yan","doi":"10.1016/j.physleta.2024.130057","DOIUrl":"10.1016/j.physleta.2024.130057","url":null,"abstract":"<div><div>Achieving multiple perfect absorptions from ultraviolet (UV) to near-infrared (IR) region is practically important for metamaterial-based efficient harvesting of photons and biosensor. Here, we theoretically demonstrate a triple narrow and broad perfect absorptions (PAs) from visible to UV range in a lifted metamaterial made of aluminum vertical split-ring resonators (Al VSRR) on silica nanostrip /Al mirror. The three simultaneously achieved narrowband and broadband PAs with bandwidth of 283.3 nm, 8.9 nm and 18.2 nm are excited from magnetic plasmon resonance, surface plasmons polariton and plasmon standing wave mode, respectively, which is further explained by the impedance matching theory. The triple-band absorption peaks are further tailored by changing the size of the structure. The group index of the lifted Al VSRR array can reach as large as 2.5 × 10<sup>3</sup> in the UV range. Moreover, due to the designed metamaterial being lifted with the reduced substrate effect, the figure of merit (<em>FoM</em>*) and sensitivity (<em>S</em>) in the UV range are as high as 1.1 × 10<sup>6</sup> and 306 nm per refractive index unit (306 nm/RIU), respectively. The proposed lifted metamaterial could have a considerable effect on the development of various UV plasmonic applications, including slow light nanodevices and optical sensor.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130057"},"PeriodicalIF":2.3,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-09DOI: 10.1016/j.physleta.2024.130047
Yann Berquin
This short study investigates the link between kernel methods and quantum mechanics. Density operators representing ensembles of pure states of sample wave functions are used in place of probability densities and Kraus operator is used to embed samples. Results show that using density operators associated to different quantum systems along with embedded samples allows to recover kernel density estimation as well as kernel mean embedding equations. Results are illustrated with a simple example using discrete orthogonal wavelet transform.
{"title":"Kernel mean embedding vs kernel density estimation: A quantum perspective","authors":"Yann Berquin","doi":"10.1016/j.physleta.2024.130047","DOIUrl":"10.1016/j.physleta.2024.130047","url":null,"abstract":"<div><div>This short study investigates the link between kernel methods and quantum mechanics. Density operators representing ensembles of pure states of sample wave functions are used in place of probability densities and Kraus operator is used to embed samples. Results show that using density operators associated to different quantum systems along with embedded samples allows to recover kernel density estimation as well as kernel mean embedding equations. Results are illustrated with a simple example using discrete orthogonal wavelet transform.</div></div>","PeriodicalId":20172,"journal":{"name":"Physics Letters A","volume":"528 ","pages":"Article 130047"},"PeriodicalIF":2.3,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142650676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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