Wenbin Lv, Taotao Zheng, Han Cao, Jinyang He, Chudong Xu, Ming-Hui Lu
Non-Hermitian factors play a key role in introducing changes to the topology of acoustic systems, by significantly expanding the classification of topological phases beyond traditional Hermitian theory and presenting challenges to the conventional bulk–boundary correspondence. Traditional Hermitian theory cannot fully describe the complicated behavior of systems interacting with their environment, thus non-Hermitian theory emerged. Currently, most non-Hermitian topological systems derive their phases from Hermitian components, which entails concurrently considering the gain and loss of the system. In the study of higher-order topological insulators, higher-order topological states are usually achieved by modulating coupling strengths. While traditionally it is viewed that dissipation in topological systems is detrimental to the topological states, recent research studies have challenged this perspective. The nontrivial topology can arise by introducing loss of a specific configuration in a trivial phase. In this study, through finite-element simulations of coupled acoustic cavity systems from one-dimensional to three-dimensional structure, it is illustrated how intentionally introducing non-Hermitian loss can induce the higher-order topology. More crucially, we have simulated the acoustic local density of states (LDOS) and calculated fractional charge modes and can directly observe and prove through LDOS that introducing loss can convert a trivial system into a topological one. Both theoretical and simulated results show that the LDOS can be used to calculate fractional charge modes, effectively characterizing higher-order topological states in non-Hermitian acoustic systems. This study carves out a research pathway for the future of non-Hermitian acoustic topology.
{"title":"Characterizing the non-Hermitian route to higher-order topology via fractional mode charges in acoustic systems","authors":"Wenbin Lv, Taotao Zheng, Han Cao, Jinyang He, Chudong Xu, Ming-Hui Lu","doi":"10.1063/5.0238920","DOIUrl":"https://doi.org/10.1063/5.0238920","url":null,"abstract":"Non-Hermitian factors play a key role in introducing changes to the topology of acoustic systems, by significantly expanding the classification of topological phases beyond traditional Hermitian theory and presenting challenges to the conventional bulk–boundary correspondence. Traditional Hermitian theory cannot fully describe the complicated behavior of systems interacting with their environment, thus non-Hermitian theory emerged. Currently, most non-Hermitian topological systems derive their phases from Hermitian components, which entails concurrently considering the gain and loss of the system. In the study of higher-order topological insulators, higher-order topological states are usually achieved by modulating coupling strengths. While traditionally it is viewed that dissipation in topological systems is detrimental to the topological states, recent research studies have challenged this perspective. The nontrivial topology can arise by introducing loss of a specific configuration in a trivial phase. In this study, through finite-element simulations of coupled acoustic cavity systems from one-dimensional to three-dimensional structure, it is illustrated how intentionally introducing non-Hermitian loss can induce the higher-order topology. More crucially, we have simulated the acoustic local density of states (LDOS) and calculated fractional charge modes and can directly observe and prove through LDOS that introducing loss can convert a trivial system into a topological one. Both theoretical and simulated results show that the LDOS can be used to calculate fractional charge modes, effectively characterizing higher-order topological states in non-Hermitian acoustic systems. This study carves out a research pathway for the future of non-Hermitian acoustic topology.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"19 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
R. A. Gallivan, J. Manser, A. Michelini, N. Toncich, N. Abando Beldarrain, C. Vockenhuber, A. Müller, H. Galinski
Ternary transition metal nitrides (TMNs) promise to significantly expand the material design space by opening new functionality and enhancing existing properties. However, most systems have only been investigated computationally, and limited understanding of their stabilizing mechanisms restricts translation to experimental synthesis. To better elucidate key factors in designing ternary TMNs, we experimentally fabricate and analyze the physical properties of the ternary Zr–Pt–N system. Structural analysis and density functional theory modeling demonstrate that Pt substitutes nitrogen on the nonmetallic sublattice, which destabilizes the rock salt structure and forms a complex cubic phase. We also show insolubility of Pt in the Zr–Pt–N at 45 at. % with the formation of a secondary Pt-rich phase. The measured reduced plasma frequency, decrease in resistivity, and decrease in hardness reflect a dominance of metallic behavior in bonding. Additionally, we observe the exsolution of Pt nano precipitates from the Zr–Pt–N films upon annealing as well as degradation in the nitridic film's thermal stability. Even at low concentrations (1%), Pt facilitates a solid reaction with the Si substrate that is otherwise inaccessible in ZrN films.
{"title":"Physical properties and thermal stability of zirconium platinum nitride thin films","authors":"R. A. Gallivan, J. Manser, A. Michelini, N. Toncich, N. Abando Beldarrain, C. Vockenhuber, A. Müller, H. Galinski","doi":"10.1063/5.0239539","DOIUrl":"https://doi.org/10.1063/5.0239539","url":null,"abstract":"Ternary transition metal nitrides (TMNs) promise to significantly expand the material design space by opening new functionality and enhancing existing properties. However, most systems have only been investigated computationally, and limited understanding of their stabilizing mechanisms restricts translation to experimental synthesis. To better elucidate key factors in designing ternary TMNs, we experimentally fabricate and analyze the physical properties of the ternary Zr–Pt–N system. Structural analysis and density functional theory modeling demonstrate that Pt substitutes nitrogen on the nonmetallic sublattice, which destabilizes the rock salt structure and forms a complex cubic phase. We also show insolubility of Pt in the Zr–Pt–N at 45 at. % with the formation of a secondary Pt-rich phase. The measured reduced plasma frequency, decrease in resistivity, and decrease in hardness reflect a dominance of metallic behavior in bonding. Additionally, we observe the exsolution of Pt nano precipitates from the Zr–Pt–N films upon annealing as well as degradation in the nitridic film's thermal stability. Even at low concentrations (1%), Pt facilitates a solid reaction with the Si substrate that is otherwise inaccessible in ZrN films.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"81 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Yi Zhang, Xiaojun Mao, Xi Chang, Jinghao Xie, Yueping Niu, Shangqing Gong, Min Qian
Perovskite memristors have garnered significant interest for their potential simulating artificial synapses; however, the presence of the toxic lead-based perovskites has hindered advancements in this field. In this work, a nontoxic, thickness-controllable Cs3Cu2I5 perovskite functional layer is synthesized through a dual-source vapor deposition for the Ag/Cs3Cu2I5/ITO memristor. The co-evaporation method shows advantages of various element, controllable atomic ratio and thickness, free impurity, and continuously uniform film. This device demonstrates an operating voltage of 1.2 V, a low power consumption of 0.013 W, a retention time exceeding 104 s, and an endurance of over 400 cycles. The synaptic behavior is emulated using the memristor, focusing on phenomena such as short-term potentiation and depression, paired-pulse facilitation, and spike-time-dependent plasticity. The migration of Na+ and Cl− ions, which occurs between the synaptic cleft and the postsynaptic membrane in biological synapses, is analogously represented by the movement of Ag+ ions between functional layer and the bottom electrode of the memristor. This process is further analyzed using the Hodgkin–Huxley neuron model. The Cs3Cu2I5-based memristor shows considerable promise for applications in storage systems and artificial synapses.
{"title":"Resistive switching and artificial synapses performance of co-evaporated Cs3Cu2I5 films","authors":"Yi Zhang, Xiaojun Mao, Xi Chang, Jinghao Xie, Yueping Niu, Shangqing Gong, Min Qian","doi":"10.1063/5.0235918","DOIUrl":"https://doi.org/10.1063/5.0235918","url":null,"abstract":"Perovskite memristors have garnered significant interest for their potential simulating artificial synapses; however, the presence of the toxic lead-based perovskites has hindered advancements in this field. In this work, a nontoxic, thickness-controllable Cs3Cu2I5 perovskite functional layer is synthesized through a dual-source vapor deposition for the Ag/Cs3Cu2I5/ITO memristor. The co-evaporation method shows advantages of various element, controllable atomic ratio and thickness, free impurity, and continuously uniform film. This device demonstrates an operating voltage of 1.2 V, a low power consumption of 0.013 W, a retention time exceeding 104 s, and an endurance of over 400 cycles. The synaptic behavior is emulated using the memristor, focusing on phenomena such as short-term potentiation and depression, paired-pulse facilitation, and spike-time-dependent plasticity. The migration of Na+ and Cl− ions, which occurs between the synaptic cleft and the postsynaptic membrane in biological synapses, is analogously represented by the movement of Ag+ ions between functional layer and the bottom electrode of the memristor. This process is further analyzed using the Hodgkin–Huxley neuron model. The Cs3Cu2I5-based memristor shows considerable promise for applications in storage systems and artificial synapses.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"44 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Lihao Zhang, Xiaoyu Wang, Qi Li, Haibo Xie, Liangliang Zhang, Lei Zhang, Jie Pan, Yingchun Cheng, Zhe Wang
Atomically thin materials with coupled magnetic and electric polarization are critical for developing energy-efficient and high-density spintronic devices, yet they remain scarce due to often conflicting requirements of stabilizing both magnetic and electric orders. The recent discovery of the magnetoelectric effect in the 2D stripy antiferromagnet CrOCl highlights this semiconductor as a promising platform to explore electric field effects on magnetoresistance. In this study, we systematically investigate the magnetoresistance in tunneling junctions of bilayer and monolayer CrOCl. We observe that the transition from antiferromagnetic to ferrimagnetic phases in both cases induces a positive magnetoresistance at low bias voltages, which reverses to a negative value at higher bias voltages. This polarity reversal is attributed to the additional electric dipoles present in the antiferromagnetic state, as supported by our theoretical calculations. These findings suggest a pathway for the electric control of spintronic devices and underscore the potential of 2D magnets like CrOCl in advancing energy-efficient spintronic applications.
{"title":"Bias voltage driven tunneling magnetoresistance polarity reversal in 2D stripy antiferromagnet CrOCl","authors":"Lihao Zhang, Xiaoyu Wang, Qi Li, Haibo Xie, Liangliang Zhang, Lei Zhang, Jie Pan, Yingchun Cheng, Zhe Wang","doi":"10.1063/5.0238384","DOIUrl":"https://doi.org/10.1063/5.0238384","url":null,"abstract":"Atomically thin materials with coupled magnetic and electric polarization are critical for developing energy-efficient and high-density spintronic devices, yet they remain scarce due to often conflicting requirements of stabilizing both magnetic and electric orders. The recent discovery of the magnetoelectric effect in the 2D stripy antiferromagnet CrOCl highlights this semiconductor as a promising platform to explore electric field effects on magnetoresistance. In this study, we systematically investigate the magnetoresistance in tunneling junctions of bilayer and monolayer CrOCl. We observe that the transition from antiferromagnetic to ferrimagnetic phases in both cases induces a positive magnetoresistance at low bias voltages, which reverses to a negative value at higher bias voltages. This polarity reversal is attributed to the additional electric dipoles present in the antiferromagnetic state, as supported by our theoretical calculations. These findings suggest a pathway for the electric control of spintronic devices and underscore the potential of 2D magnets like CrOCl in advancing energy-efficient spintronic applications.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"7 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 wavy interface and its formation mechanism in magnesium–aluminum joints fabricated by electromagnetic pulse welding are investigated. This work reveals the wavy interfaces are produced by the shock wave-induced Kelvin–Helmholtz (K–H) instability. The shock wave generated at the collision point propagates forward along the collision angle and undergoes refraction and reflection at the boundaries, reaching the bonding interface and causing disturbances. It leads to K–H instability at the bonding interface, periodically generating waves. The re-reflection of the shock wave also leads to the secondary K–H instability, which creates the secondary wave with a smaller amplitude on the original wave. Based on this principle, a shock wave-induced K–H instability simulation model was also established to predict the wavy interface length.
{"title":"Wavy interface formation mechanism during magnesium–aluminum electromagnetic pulse welding","authors":"C. X. Li, Z. X. Wu, D. Chen, Y. H. Shu, Y. Zhou","doi":"10.1063/5.0229108","DOIUrl":"https://doi.org/10.1063/5.0229108","url":null,"abstract":"The wavy interface and its formation mechanism in magnesium–aluminum joints fabricated by electromagnetic pulse welding are investigated. This work reveals the wavy interfaces are produced by the shock wave-induced Kelvin–Helmholtz (K–H) instability. The shock wave generated at the collision point propagates forward along the collision angle and undergoes refraction and reflection at the boundaries, reaching the bonding interface and causing disturbances. It leads to K–H instability at the bonding interface, periodically generating waves. The re-reflection of the shock wave also leads to the secondary K–H instability, which creates the secondary wave with a smaller amplitude on the original wave. Based on this principle, a shock wave-induced K–H instability simulation model was also established to predict the wavy interface length.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"19 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713260","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
We report operando measurements of the Li-ion distribution in the anode and cathode of a coin-type all-solid-state battery in the charged and discharged states via Compton scattering using high-energy synchrotron radiation x-ray analysis. From the line shape pattern analysis of the Compton scattering x-ray spectrum, we accurately observed the Li-ion distribution within the cathode and anode during the charging/discharging of a real coin-shaped battery in an SUS casing. This study discusses the difference in Li-ion distribution between the cathode and anode and compares the Li-ion distribution of the battery after 20 charge–discharge cycles with those of a fresh battery.
我们报告了利用高能同步辐射 X 射线分析，通过康普顿散射测量硬币型全固态电池正负极在充放电状态下的锂离子分布。通过对康普顿散射 X 射线光谱的线形模式分析，我们准确地观测到了在 SUS 外壳中的真实硬币型电池在充放电过程中正负极内的锂离子分布。本研究讨论了正负极之间锂离子分布的差异，并比较了 20 次充放电循环后电池的锂离子分布与新鲜电池的锂离子分布。
{"title":"Operando Li-ion distribution measurement of all-solid-state batteries by Compton-scattered x rays","authors":"Kazuki Nakamura, Kosuke Suzuki, Futoshi Utsuno, Kodai Takano, Tomoya Ando, Kazushi Hoshi, Naruki Tsuji, Hiroshi Sakurai","doi":"10.1063/5.0238369","DOIUrl":"https://doi.org/10.1063/5.0238369","url":null,"abstract":"We report operando measurements of the Li-ion distribution in the anode and cathode of a coin-type all-solid-state battery in the charged and discharged states via Compton scattering using high-energy synchrotron radiation x-ray analysis. From the line shape pattern analysis of the Compton scattering x-ray spectrum, we accurately observed the Li-ion distribution within the cathode and anode during the charging/discharging of a real coin-shaped battery in an SUS casing. This study discusses the difference in Li-ion distribution between the cathode and anode and compares the Li-ion distribution of the battery after 20 charge–discharge cycles with those of a fresh battery.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"36 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Cedric Schmitt, Simone Sotgiu, Stefan Enzner, Jonas Erhardt, Elena Stellino, Domenico Di Sante, Giorgio Sangiovanni, Ralph Claessen, Simon Moser, Leonetta Baldassarre
Intercalating two-dimensional quantum materials beneath a sheet of graphene provides effective environmental protection and facilitates ex situ device fabrication. However, developing a functional device requires rapid, large-scale screening methods to evaluate the quality of the intercalant, which to date can be monitored only by slow, ultra-high vacuum-based surface science techniques. In this study, we utilize ex situ Raman micro-spectroscopy to optically and nondestructively identify the quantum spin Hall insulator indenene, a monolayer of indium sandwiched between a SiC(0001) substrate and a single sheet of graphene. Color modulation combined with indenene's distinctive low-frequency Raman fingerprint enables rapid assessment of its homogeneity and crystalline quality. Density functional perturbation theory indicates that this Raman signature originates mainly from indenene's shear and breathing modes, while additional higher order modes are tentatively attributed to defect-assisted and two-phonon Raman processes.
{"title":"All-optical quality control of indenene intercalation into graphene/SiC","authors":"Cedric Schmitt, Simone Sotgiu, Stefan Enzner, Jonas Erhardt, Elena Stellino, Domenico Di Sante, Giorgio Sangiovanni, Ralph Claessen, Simon Moser, Leonetta Baldassarre","doi":"10.1063/5.0237088","DOIUrl":"https://doi.org/10.1063/5.0237088","url":null,"abstract":"Intercalating two-dimensional quantum materials beneath a sheet of graphene provides effective environmental protection and facilitates ex situ device fabrication. However, developing a functional device requires rapid, large-scale screening methods to evaluate the quality of the intercalant, which to date can be monitored only by slow, ultra-high vacuum-based surface science techniques. In this study, we utilize ex situ Raman micro-spectroscopy to optically and nondestructively identify the quantum spin Hall insulator indenene, a monolayer of indium sandwiched between a SiC(0001) substrate and a single sheet of graphene. Color modulation combined with indenene's distinctive low-frequency Raman fingerprint enables rapid assessment of its homogeneity and crystalline quality. Density functional perturbation theory indicates that this Raman signature originates mainly from indenene's shear and breathing modes, while additional higher order modes are tentatively attributed to defect-assisted and two-phonon Raman processes.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"59 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Continuous miniaturization of electronic components puts higher demands on the heat dissipation of the micro-systems, which requires environmental friendliness, good heat exchange capability, and high-performance micro-refrigeration materials. Here, we developed a Ni–Mn–Fe–In microwire fabricated by the Taylor–Ulitovsky method, showing ⟨001⟩A orientation close to the axial direction of microwire. Due to the large volume change ΔV/V (−1.24%), the large entropy change ΔStr of 43.6 J kg−1 K−1 was achieved in the microwire. Owing to the low driving force of the microwire with a single crystalline of ⟨001⟩A orientation close to the axial direction of microwire, large adiabatic temperature change of −5.7 K was achieved at room temperature after removing a low stress of 120 MPa. Thus, high specific adiabatic temperature change of 47.5 K/GPa was obtained in the microwire, which is the highest value among all the reported low-dimension elastocaloric materials, including thin films/foils, microwires/wires, and ribbons. The outstanding comprehensive properties give this microwire a great application potential in miniaturization and compactness of refrigeration devices.
{"title":"Large room-temperature elastocaloric effect and enhanced specific adiabatic temperature change of Ni–Mn-based shape memory microwire","authors":"Zhen Chen, Yuxian Cao, Liying Sun, Xiaoming Sun, Daoyong Cong","doi":"10.1063/5.0239552","DOIUrl":"https://doi.org/10.1063/5.0239552","url":null,"abstract":"Continuous miniaturization of electronic components puts higher demands on the heat dissipation of the micro-systems, which requires environmental friendliness, good heat exchange capability, and high-performance micro-refrigeration materials. Here, we developed a Ni–Mn–Fe–In microwire fabricated by the Taylor–Ulitovsky method, showing ⟨001⟩A orientation close to the axial direction of microwire. Due to the large volume change ΔV/V (−1.24%), the large entropy change ΔStr of 43.6 J kg−1 K−1 was achieved in the microwire. Owing to the low driving force of the microwire with a single crystalline of ⟨001⟩A orientation close to the axial direction of microwire, large adiabatic temperature change of −5.7 K was achieved at room temperature after removing a low stress of 120 MPa. Thus, high specific adiabatic temperature change of 47.5 K/GPa was obtained in the microwire, which is the highest value among all the reported low-dimension elastocaloric materials, including thin films/foils, microwires/wires, and ribbons. The outstanding comprehensive properties give this microwire a great application potential in miniaturization and compactness of refrigeration devices.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"183 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
Yihao Xue, Guan Wang, Yu Cai, Huaxia Deng, Xinglong Gong
In nature, animals have evolved various shapes of pupils to detect moving targets with diverse postures effectively. Motivated by the concept of the adaptable aperture pupil, we present a pupil-inspired foveated single-pixel imaging approach featuring a variable foveal, enhancing the correlation between the fovea regions and targets in the scene. Furthermore, this pupil-inspired foveated strategy not only regulates the field of view by mimicking the expansion and contraction of the iris but also aids in target tracking by foveal saccade mimicry. In this way, our method improves the maximum utilization of high-resolution areas by 63%. The methodologies outlined in this study optimize the arrangement of pixel cells during the sampling process and promise to be a practical method enabling single-pixel imaging in dynamic scenes.
{"title":"Adaptive aperture pupil-inspired foveated single-pixel imaging for multi-posture moving targets","authors":"Yihao Xue, Guan Wang, Yu Cai, Huaxia Deng, Xinglong Gong","doi":"10.1063/5.0237530","DOIUrl":"https://doi.org/10.1063/5.0237530","url":null,"abstract":"In nature, animals have evolved various shapes of pupils to detect moving targets with diverse postures effectively. Motivated by the concept of the adaptable aperture pupil, we present a pupil-inspired foveated single-pixel imaging approach featuring a variable foveal, enhancing the correlation between the fovea regions and targets in the scene. Furthermore, this pupil-inspired foveated strategy not only regulates the field of view by mimicking the expansion and contraction of the iris but also aids in target tracking by foveal saccade mimicry. In this way, our method improves the maximum utilization of high-resolution areas by 63%. The methodologies outlined in this study optimize the arrangement of pixel cells during the sampling process and promise to be a practical method enabling single-pixel imaging in dynamic scenes.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"16 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142713253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}
This study investigates the propagation characteristics of spin waves in an yttrium iron garnet waveguide using a vector network analyzer and a real-time oscilloscope. We confirm the propagation of backward volume magnetostatic spin waves in the linear regime. Solitary spin-wave formation was observed, and the transition from linear to nonlinear response was verified by establishing a threshold power. In the nonlinear regime, collision experiments between two spin waves were conducted, revealing a dependence of attenuation on the input carrier frequency. A comparison with the transmission loss curve confirms the correlation between attenuation and the position of “frequency regions with strong dispersion.” Notably, only within a specific frequency range among these regions do the colliding spin waves maintain their shapes and momenta, passing through each other without dissipation. This remarkable phenomenon is crucial for dissipation-free information transfer. Our findings offer valuable insights into spin-wave behavior, particularly for developing spin-wave-based logic and long-distance magnonic soliton information transfer.
{"title":"Frequency-dependent breakdown of backward volume spin-wave soliton formation","authors":"Tokiya Iwata, Shoki Nezu, Koji Sekiguchi","doi":"10.1063/5.0213617","DOIUrl":"https://doi.org/10.1063/5.0213617","url":null,"abstract":"This study investigates the propagation characteristics of spin waves in an yttrium iron garnet waveguide using a vector network analyzer and a real-time oscilloscope. We confirm the propagation of backward volume magnetostatic spin waves in the linear regime. Solitary spin-wave formation was observed, and the transition from linear to nonlinear response was verified by establishing a threshold power. In the nonlinear regime, collision experiments between two spin waves were conducted, revealing a dependence of attenuation on the input carrier frequency. A comparison with the transmission loss curve confirms the correlation between attenuation and the position of “frequency regions with strong dispersion.” Notably, only within a specific frequency range among these regions do the colliding spin waves maintain their shapes and momenta, passing through each other without dissipation. This remarkable phenomenon is crucial for dissipation-free information transfer. Our findings offer valuable insights into spin-wave behavior, particularly for developing spin-wave-based logic and long-distance magnonic soliton information transfer.","PeriodicalId":8094,"journal":{"name":"Applied Physics Letters","volume":"16 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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