检索结果-内蒙古大学图书馆

Topological phases in photonic microring lattices with projective symmetry

Physical Review A 2024年第1期109卷 013516-013516页

作者： Yang Liu Chuang Jiang Wanting Wen Yiling Song Xiaohong Li Peixiang Lu Shaolin Ke Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan 430205 China Department of Physics Wenzhou University Zhejiang 325035 China Guangdong Intelligent Robotics Institute Dongguan 523808 China

Symmetry plays a key role in classifying topological phases, which can be enriched by the projective symmetry group in the presence of artificial gauge fields (AGFs). Here, we utilize two-dimensional (2D) photonic microring lattices to create three different topological states based on projective symmetry. By engineering link rings, we are able to flexibly manipulate the AGFs and coupling magnitude. As each plaquette carries a π flux, the two translation symmetries of a rectangle microring lattice are projectively represented. By applying different types of dimerization, we tune the spatial space to break translation symmetry and achieve a Möbius topological insulator with twisted edge bands and a graphenelike topological semimetal with flat bands, which we reflect by unique excitation spectra and field distributions. Additionally, by changing the configuration of gauge flux, the mirror and translation operators become anticommutative, leading to the fractal translation of the Brillouin zone. As a result, the band structure of topological edge modes experiences twice the period in momentum space. All results are confirmed by full-wave simulation. Our study has the potential to construct unprecedented photonic topological insulators benefiting from gauge fields.

关键词： Nanophotonics Photonics Topological effects in photonic systems optical microcavities

来源：评论

学校读者我要写书评

暂无评论

Topological corner states for wireless power transfer

引用

Reviews in Physics 2025年 13卷

作者： Jiang, Jie Hu, Shengyu Guo, Zhiwei Ke, Shaolin Wu, Xian Wu, Yuntai Wang, Yuqian Jiang, Haitao Yang, Yaping Chen, Hong MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Science and Engineering Tongji University Shanghai 200092 China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan430205 China

Wireless power transfer (WPT) technology has seen significant advancements, but traditional methods often struggle to meet the demands of complex application scenarios, such as simultaneously powering multiple devices wirelessly. In this paper, we explore the potential of topological corner state (TCS) for multi-load WPT, supported by both theoretical and experimental results. In two-dimensional Su–Schrieffer–Heeger (SSH) systems with only nearest-neighbor (NN) coupling, quadruple TCSs offer an efficient and robust solution for multi-load WPT. Furthermore, by developing bilayer topological structures and incorporating next-nearest-neighbor (NNN) coupling, we achieve dual TCSs and create a flexible platform for multi-load WPT. These findings highlight the diverse topological phenomena enabled by higher-order phases and present a practical approach for various wireless applications, including wireless sensing and communications. © 2025 The Author(s)

关键词： Inductive power transmission

来源：评论

学校读者我要写书评

暂无评论

Finite-time Mittag-Leffler synchronization of fractional-order delayed memristive neural networks with parameters uncertainty and discontinuous activation functions

引用

Chinese Physics B 2020年第4期29卷 127-138页

作者： Chong Chen Zhixia Ding Sai Li Liheng Wang Hubei Key Laboratory of Optical Information and Pattern Recognition School of Electrical and Information EngineeringWuhan Institute of TechnologyWuhan 430205China

The finite-time Mittag-Leffler synchronization is investigated for fractional-order delayed memristive neural networks(FDMNN)with parameters uncertainty and discontinuous activation *** relevant results are obtained under the framework of Filippov for such ***,the novel feedback controller,which includes the discontinuous functions and time delays,is proposed to investigate such ***,the conditions on finite-time Mittag-Leffler synchronization of FDMNN are established according to the properties of fractional-order calculus and inequality analysis *** the same time,the upper bound of the settling time for Mittag-Leffler synchronization is accurately *** addition,by selecting the appropriate parameters of the designed controller and utilizing the comparison theorem for fractional-order systems,the global asymptotic synchronization is achieved as a ***,a numerical example is given to indicate the correctness of the obtained conclusions.

关键词： fractional-order delayed memristive neural networks(FDMNN) parameters uncertainty discontinuous activation functions finite-time Mittag-Leffler synchronization

来源：评论

学校读者我要写书评

暂无评论

TCPNet: A 3D Point Cloud Classification Model Based on the Advanced CNN and Transformer

TCPNet: A 3D Point Cloud Classification Model Based on the A...

引用

International Conference on Artificial Intelligence and Computer information Technology (AICIT)

作者： Jinmeng Wu Jingwei Ma Hanyu Hong Yanbin Hao Lei Ma Lei Wang Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan China School of Information Science and Technology University of Science and Technology of China Anhui China

ISBN: (数字)9798350365443

ISBN: (纸本)9798350365450

Transformer and Convolutional Neural Network (CNN) are currently two important models in the field of deep learning. Among them, Transformer has strong global perception ability but weak local perception ability, and CNN precisely compensates for this. CNN has strong local perception ability, so in order to combine the advantages of both, we propose a 3D classification model TCPNet based on Transformer and CNN. We first use Transformer to extract the global features of the point cloud, and then concatenate a CNN network to enhance the detail perception ability, so that the network can better understand the 3D point cloud. The experimental results on the ModelNet40 and ScanObjectNN datasets show that our method can effectively achieve 3D classification tasks. On ModelNet40, an accuracy of 93.6% can be achieved. On the most difficult variant PB-T50-RS of ScanObjectNN, an accuracy of 83.93% can be achieved.

关键词： Point cloud compression Solid modeling Three-dimensional displays Accuracy Convolution Transformers Feature extraction Convolutional neural networks information technology information exchange

来源：评论

学校读者我要写书评

暂无评论

Toroidal dipole-modulated dipole-dipole double-resonance in colloidal gold rod-cup nanocrystals for improved SERS and secondharmonic generation

引用

Nano Research 2022年第10期15卷 9461-9469页

作者： Hao-Sen Kang Wen-Qin Zhao Tao Zhou Liang Ma Da-Jie Yang Xiang-Bai Chen Si-Jing Ding Qu-Quan Wang Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of TechnologyWuhan 430205China School of Mathematics and Physics China University of Geosciences(Wuhan)Wuhan 430074China Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China School of Science Department of PhysicsSouthern University of Science and TechnologyShenzhen 518055China

Colloidal metal nanocrystals(NCs)show great potential in plasmon-enhanced spectroscopy owing to their attractive and structure-depended plasmonic ***,unique Au rod-cup NCs,where Au nanocups are embedded on the one or two ends of Au nanorods(NRs),are successfully prepared for the first time via a controllable wet-chemistry *** Au rod-cup NCs possess multiple plasmon modes including transverse and longitudinal electric dipole(TED and LED),magnetic dipole(MD),and toroidal dipole(TD)modulated LED resonances,producing large extinction cross-section and huge near-field enhancements for plasmon-enhanced ***,Au rod-cup NCs with two embedded cups show excellent surface-enhanced Raman spectroscopy(SERS)performance than Au NRs(75.6-fold enhancement excited at 633 nm)on detecting crystal violet owing to the strong electromagnetic hotspots synergistically induced by MD,LED,and TED-based plasmon coupling between Au cup and ***,the strong TD-modulated dipole-dipole double-resonance and MD modes in Au rod-cup NCs bring a 37.3-fold enhancement of second-harmonic generation intensity compared with bare Au NRs,because they can efficiently harvest photoenergy at fundamental frequency and generate large near-field enhancements at second-harmonic *** findings provide a strategy for designing optical nanoantennas for plasmon-enhanced applications based on multiple plasmon modes.

关键词： plasmon toroidal dipole near-field enhancement surface-enhanced Raman spectroscopy(SERS) second-harmonic generation

来源：评论

学校读者我要写书评

暂无评论

Floquet engineering Dirac bands in synthetic frequency lattices

引用

Physical Review A 2023年第6期108卷 063515-063515页

作者： Lingzhi Zheng Bing Wang Chengzhi Qin Shuyue Chen Lange Zhao Shulin Wang Weiwei Liu Peixiang Lu School of Physics and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China Hubei Key laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan 430205 China

A waveguide coupler under periodically cascaded dielectric modulation is proposed to generate a Floquet lattice in synthetic frequency dimension. The Floquet bands may hold linear in the entire Brillouin zone, referred to as Floquet Dirac bands and giving rise to nondiffracting frequency shifts. The direction of frequency shift depends on the component of incident transverse modes, analogous to the spin-momentum locking realized in driven ultracold atoms recently. Furthermore, the shape of Floquet bands can be flexibly adjusted by applying external modulation voltage, resulting in a tunable group velocity and diffraction coefficient. The discrete diffraction and dynamic localization are also demonstrated in the Floquet frequency lattice. The study provides a versatile platform to explore multiband Floquet lattice physics in synthetic dimensions, and may find applications in spectral manipulation, mode conversion, and mode-division demultiplexing.

关键词： Electro-optic effects Frequency conversion Interference & diffraction of light Optics & lasers Photonics Waveguides

来源：评论

学校读者我要写书评

暂无评论

Spheroidal-wave analysis of time delay in molecular reconstruction of attosecond beating by interference of two-photon transitions around a Cooper-like minimum

引用

Physical Review A 2023年第1期108卷 013112-013112页

作者： Qinghua Ke Yueming Zhou Yijie Liao Min Li Kunlong Liu Peixiang Lu School of Physics and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan 430205 China

By numerically solving the three-dimensional time-dependent Schrödinger equation, we have studied the energy- and angle-resolved time delay in H2+ photoionization using the reconstruction of attosecond beating by the interference of two-photon transition (RABITT) technique. Around the electron energy of Ec∼1.4 a.u., the RABITT time delay varies significantly with the energy and emission angle. The time delay changes from positive values to negative values as the increasing energy and emission angle. We have applied the spheroidal wave analysis to reveal this interesting time delay. By analyzing the time-delay dependent modulation of the anisotropic parameters, the energy and angle dependence of the time delay is well interpreted from the perspective of spheroidal wave interference. It shows that the Cooper-like minimum of a p spheroidal wave is responsible for this sign change of the RABITT time delay.

关键词： Atomic & molecular processes in external fields Atomic & molecular structure Photoemission

来源：评论

学校读者我要写书评

暂无评论

Asymmetric Switching of Edge Modes by Dynamically Encircling Multiple Exceptional Points

引用

Physical Review Applied 2023年第6期19卷 064050-064050页

作者： Yicong Zhang Weiwei Liu Shuaifei Ren Tianyan Chai Yanan Wang Hua Long Kai Wang Bing Wang Peixiang Lu Wuhan National Laboratory for Optoelectronics and School of Physics Huazhong University of Science and Technology Wuhan 430074 China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan 430205 China

Dynamically encircling exceptional points (EPs) in the parameter space of a non-Hermitian system has drawn widespread attention for realizing asymmetric mode switching and related applications. While previous works have been restricted to two-level systems, the switching between edge states in a multistate system that contains more complex dynamics remains to be explored. Herein, asymmetric switching of edge modes in multistate systems is demonstrated by encircling multiple EPs. A multistate non-Hermitian system containing multiple EPs is constructed based on a one-dimensional lattice, which can support four edge-localized modes. Dynamically encircling the EPs in parameter space leads to a specific edge mode surviving to the end, determined by the encircling direction. Correspondingly, optical waveguide arrays are designed to investigate mode evolution through refractive index modulation. Simulated results show that clockwise (counterclockwise) encirclement leads to an output mode localized at the left (right) side of the waveguide array with a phase difference of 0 (π), regardless of the input modes; this excellently illustrates the asymmetric switching of edge modes in a multistate system. Moreover, such an effect can be extended to the multistate system with an arbitrary number of EPs. This work enables investigation of interesting effects in non-Hermitian physics by engineering the EPs and topological properties, especially for complex multistate systems, which will be useful for developing functional nanophotonic devices.

关键词： Nanophotonics Symmetry protected topological states Topological effects in photonic systems Non-Hermitean systems Waveguide arrays PT-symmetry Adiabatic approximation Schroedinger equation

来源：评论

学校读者我要写书评

暂无评论

Spin-polarized electron vortices produced in single-photon ionization

引用

Physical Review A 2023年第3期107卷 033108-033108页

作者： Yibo Hu Qiangfei Ma Kunlong Liu Yidian Tian Min Li Yueming Zhou Peixiang Lu Wuhan National Laboratory for Optoelectronics and School of Physics Huazhong University of Science and Technology Wuhan 430074 China Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of Technology Wuhan 430205 China Optics Valley Laboratory Hubei 430074 China

We theoretically investigate a scheme to produce spin-polarized electrons based on the vortex interference of the photoelectrons in single-photon ionization. A pair of time-delayed counterrotating circularly polarized pulses are applied to ionize the rare-gas-atom krypton. The results show that the vortex-shaped photoelectron momentum distributions for the ionization channels of J=1/2 and J=3/2, as well as those associated with the initial p+ and p− orbitals, can be well dislocated in momentum space, leading to the spin polarization exceeding 50%. Furthermore, by modifying the time delay, the wavelength, and the relative phase of the pulse pair, we show that the kinetic energy as well as the ejection angle of the spin-polarized electrons can be flexibly controlled in the present scheme.

关键词： Single- and few-photon ionization & excitation Ultrafast phenomena

来源：评论

学校读者我要写书评

暂无评论

Ablation Characteristic and Preparation of Controllable Periodic Surface Structure of Zno by Femtosecond Laser

SSRN

引用

SSRN 2023年

作者： Liu, Tongfeng Zuo, Pei Li, Fang Tian, Hong Wu, Ruolin Hu, Lifei Huang, Helang Liu, Junjie Zhu, Di Qian, Xiaodong School of Mechanical and Electrical Engineering Hubei Key Laboratory of Optical Information and Pattern Recognition School of Optical Information and Energy Engineering Wuhan Institute of Technology Wuhan430073 China

Zinc oxide (ZnO), an intensively concerned semiconductor material, have been widely applied in industry because of its wide band gap and high energy excitation. Surface processing and micro/nanostructures play an important role in the properties and applications of ZnO. In this work, we have investigated the effect of ablation characteristic of ZnO by varying fs parameters including the laser fluence (F), pulse delay (∆τ), polarization direction and pulse number(N). With the increase of laser fluence, melting phenomenon appears in the ablation crater. Adjusting the polarization direction of the linearly polarized femtosecond laser, the periodic structures exhibited polarization dependence. The area of surface ablation crater shows a trend of damped oscillation with the increase of femtosecond laser pulse delay. In addition, the increase of pulse number leads to the gradually shortening of the period of the surface structures and a transition phenomenon from LSFL to HSFL. Controllable periodic surface structure with a period of about 170 nm is successfully prepared on the surface of ZnO at a scanning speed of 500μm/s. © 2023, The Authors. All rights reserved.

关键词： Zinc oxide

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：