Article
Mathematics, Applied
A. V. Porubov
Summary: The features of nonlinear strain solitary waves in a metamaterial mass-in-mass lattice model were studied in the continuum limit. The coupling between the masses attached to the main chain is the main characteristic of the model. An asymptotic procedure was developed to decouple the governing continuum equations and obtain a single equation for longitudinal strains. Analytical and numerical solutions of the equation showed that the nonlinearity of the metamaterial model and the attached mass influenced the localization of strain waves and the number of generated localized waves. An improvement of the model was suggested by including a switch-on/off mechanism for the attached masses to control the localization of nonlinear strain waves in the metamaterial.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Optics
Jia-Qi Yuan, Bo Zhao, Lin-Shan Sun, Li-Ting Wu, Tian-Jing Guo, Ming Kang, Jing Chen
Summary: The study explores optical resonances in coupled meta-atoms with hybrid interaction pathways, making the hybrid optical system PT symmetric by introducing gain or loss. This allows for customization of the effective coupling rate and supports discrete super-resonant modes. At specific phases, extremely sharp peaks in transmission spectra are observed, and at exceptional points, a high-Q factor of the localized field can be obtained.
Article
Optics
Savannah Garmon, Kenichi Noba
Summary: The study focuses on a model with a PT-symmetric trimer coupled to two semi-infinite SSH leads, revealing different types of zero-energy modes and breaking of PT-symmetry. Within the parameter space corresponding to the topologically nontrivial phase, a gap opens in the eigenvalue spectrum indicating symmetry breaking, while increasing gamma leads to further localization of eigenstates. At boundary points, exceptional points can form, including higher-order EPs involving localized zero-energy states that exhibit characteristic dynamics in an evolution experiment.
Article
Chemistry, Physical
Min He, Tiankuo Xu, Yang Gao, Chaoqun Hu, Jianwang Cai, Ying Zhang
Summary: This research demonstrates the generation of mixed-type skyrmions in symmetric Pt/Co(1.55)/Pt multilayers at room temperature, showing reversible evolution dependent on magnetic field. The high D value in this structure allows for the creation of skyrmions, with Neel-type skyrmions transforming into Bloch-type as D decreases. The non-uniform D at interfaces may play a role in generating mixed-type skyrmions.
Article
Mathematics, Interdisciplinary Applications
Zhenkun Wu, Kaibo Yang, Xijun Ren, Peng Li, Feng Wen, Yuzong Gu, Lijun Guo
Summary: This study analyzes conical diffraction in space-fractional parity-time (PT) symmetry and examines the peculiar characteristics of the corresponding Floquet Bloch modes. The study finds that the band structure in this model is different from regular PT symmetry, and the linear band structure during propagation has unique properties.
CHAOS SOLITONS & FRACTALS
(2022)
Article
Astronomy & Astrophysics
Scott Lawrence, Ryan Weller, Christian Peterson, Paul Romatschke
Summary: This work critically reexamines the relationship between analytically continued Hermitian field theory and PT-symmetric field theory, finding that PT-symmetric field theory does not generally correspond to the analytic continuation of the Hermitian theory, except at high temperature where the instanton contribution can be neglected.
Article
Optics
Jiawei Zhang, Ziyao Feng, Xiankai Sun
Summary: Novel physical concepts originating from quantum mechanics, such as non-Hermitian systems and bound states in the continuum, have attracted significant interest in the optics and photonics community. In this study, a parallel cascaded-resonator system is proposed for the first time to achieve both bound states in the continuum and anti-PT symmetry simultaneously. The requirements for Fabry-Perot bound states in the continuum and anti-PT symmetry can be met by adjusting the phase shift between adjacent resonators. The proposed structure can be implemented on an integrated photonic platform and has potential applications in various fields such as optical delay and storage, nonlinear processing, sensing, and mode switching.
LASER & PHOTONICS REVIEWS
(2023)
Article
Optics
Tianrang Wang, Jian Tang, Ming Chen, Jianfeng Xiong, Hexuan Wang, Jie Xu, Shiliang Qu, Yu Cheng, Libo Yuan
Summary: We report a demonstration of an ultrafast all-optical switching with unique light control effects. The switching device effectively controls the transmission and absorption of continuous pulses and short pulses, achieving high output control and modulation bandwidth. This study provides a new structure for ultra-high speed optical data processing components in coherent networks.
Article
Physics, Multidisciplinary
Wei Huang, Songyi Liu, Yu Cheng, Jiaguang Han, Shan Yin, Wentao Zhang
Summary: This paper introduces a novel universal coupled theory for metamaterial bound states in the continuum or quasi-bound states in the continuum, providing ultra-high Q resonance for metamaterial devices with greater accuracy compared to previous theories. It accurately predicts the transmission spectrum of metamaterial BIC or quasi-BIC for the first time, making it more suitable for predicting BIC or quasi-BIC in metamaterials.
NEW JOURNAL OF PHYSICS
(2021)
Article
Multidisciplinary Sciences
Emese Toth, Balazs Banhelyi, Oliver Fekete, Maria Csete
Summary: Single and multiple layers of sub-wavelength periodic Babinet complementary patterns composed of rounded nano-object miniarrays were investigated. The azimuthal orientation and handedness (in)dependence of (cross-polarized) copolarized transmitted signal components were proven for all types of patterns. Considerable (weak) asymmetric transmission was demonstrated in extended bands exclusively for both types of copolarized (cross-polarized) signals transmitted through single layer of convex miniarrays.
SCIENTIFIC REPORTS
(2023)
Article
Nanoscience & Nanotechnology
Zhicheng Xiao, Andrea Alu
Summary: The study explores a hybrid parity-time and anti-parity-time symmetric system that supports highly tunable Fano resonances. This system can be implemented in nanophotonic and microwave circuits for real-time control of scattering line shapes, demonstrating the opportunities enabled by non-Hermitian platforms in controlling scattering line shapes for various photonic, electronic, and quantum systems. The potential applications include high-resolution imaging, switching, sensing, and multiplexing.
Article
Materials Science, Multidisciplinary
Cai Zhou, Dengyu Zhu, Dong Li, Fufu Liu, Wei Zhu, Kang Du, Mingyao Xu, Jiaxing Fang, Dequan Meng, Chuangwen Wu, Shiheng Liang, Shengxiang Wang
Summary: The magnetic domain of a Co/Pt thin film grown on a PMN-PT substrate was controlled by an electric field at room temperature. The magnetic hysteresis loops and magnetic domain state were recorded using MOKE. In the unpoled state, magnetic domain wall propagation was observed under a fixed perpendicular magnetic field. The electric-field control of the magnetic domain was demonstrated by exploiting piezostrain-mediated magnetoelectric coupling in ferromagnetic/ferroelectric heterostructures with perpendicular magnetic anisotropy, which is promising for designing future spin-transfer torque magnetoresistive random access memory devices.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Physics, Applied
K. M. Dhriti, Ashish Kumar Chowdhary, Bhagwat Singh Chouhan, Debabrata Sikdar, Gagan Kumar
Summary: In this article, a tunable and broadband metamaterial absorber in the terahertz regime is reported. The design consists of frustum-shaped dielectric structures and graphene nanoribbons, which enable near-perfect absorption for TM polarization and negligible absorption for TE polarization. Modulation of the absorption spectrum is achieved by changing the graphene conductivity with its Fermi energy.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Mechanical
Xiaoqin Bai, Rongcao Yang, Heping Jia, Juan Bai
Summary: In this paper, we investigate the dynamics and manipulation of finite energy Airy (FEA) beam in fractional system with diffraction modulation and PT-symmetric potential. We analyze the behaviors of both chirp-free and chirped FEA beams under diffraction modulation and discuss the possibility of designing diffraction modulation. We also explore the effects of diffraction modulation and PT-symmetric potential on the beam evolution.
NONLINEAR DYNAMICS
(2023)
Article
Thermodynamics
A. V. Porubov
Summary: The continuum limit of the metamaterial mass-in-mass model with additional attached mass reveals the appearance, width, and position variations of the band gaps, which are governed by the stiffness ratio of the attached masses. Numerical study shows the suppression of harmonic waves within the band gap areas and different recovery patterns for frequencies below and above the band gap values. A control mechanism based on the abrupt variation of the stiffness ratio is developed to induce phase shift, suppression, or recovery of suppressed harmonic waves. The nonlinear long wavelength generalization of the model leads to the propagation of localized waves with different amplitude and velocity.
CONTINUUM MECHANICS AND THERMODYNAMICS
(2023)
