Article
Materials Science, Multidisciplinary
Chunxu Chen, Kelson Kaj, Yuwei Huang, Xiaoguang Zhao, Richard D. Averitt, Xin Zhang
Summary: This research shows the use of reconfigurable terahertz metamaterials with tunable toroidal moments, achieved by modifying the bending angle through thermal actuation. The experiment using terahertz time-domain spectroscopy confirms the feasibility of toroidal response.
ADVANCED OPTICAL MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Hao-Yuan Tsai, Che-Chin Chen, Chun-Yen Chen, Yi-Jie Lin, Wei-Chun Chen, Hung-Pin Chen, Yu-Wei Lin, Takuo Tanaka, Ta-Jen Yen
Summary: In this study, the radiation patterns of single-split ring resonators (SSRRs) and double-split ring resonators (DSRRs) in the vertical direction were tailored by reconfiguring the resonator geometries. Vertical metamaterials were fabricated to achieve unequal arm lengths for controlling the floating split angle of the resonators. The combination of SSRRs and DSRRs effectively reconfigures the radiation direction in the infrared (IR) region.
Article
Chemistry, Physical
Ibraheem Al-Naib, Ijlal Shahrukh Ateeq
Summary: In this paper, a new approach to excite sharp asymmetric resonances using a single completely symmetric split-ring resonator (SRR) inside a rectangular waveguide is proposed. The method is based on an asymmetry in the excitation of a symmetric split-ring resonator by placing it away from the center of the waveguide along its horizontal axis. In turn, a prominent asymmetric resonance was observed in the transmission amplitude of both the simulated results and the measured data. Using a single symmetric SRR with an asymmetric distance of 6 mm from the center of a rectangular waveguide led to the excitation of a sharp resonance with a Q-factor of 314 at 6.9 GHz. More importantly, a parametric study simulating different overlayer analytes with various refractive indices revealed a wavelength sensitivity of 579,710 nm/RIU for 150 mu m analyte thickness.
Article
Physics, Applied
Jiawei Xu, Haihua Fan, Qiaofeng Dai, Haiying Liu, Sheng Lan
Summary: In this study, almost pure toroidal dipole (TD) resonance is demonstrated in a silicon hollow cylinder in the visible region. The enhanced optical coupling to TD resonance is achieved using a focused radially polarized beam illumination matching with a well-designed individual silicon nanostructure resonator. The polarization of the longitudinal electric field in the silicon hollow cylinder is critical to the formation of enhanced TD resonance, with potential applications in the local enhancement of electromagnetic fields and the design of all-dielectric nanoantennas.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Optics
Hong Wang, Yingying Yu, Rui Zeng, Bo Sun, Wenxing Yang
Summary: In this paper, an actively tunable toroidal metamaterials are proposed to achieve programmable toroidal dipole manipulations with electric control. The proof-of-concept experiments demonstrate good performance and potential applications of the proposed toroidal metamaterials.
Article
Engineering, Electrical & Electronic
Abhishek Kumar Jha, Adam Lamecki, Michal Mrozowski
Summary: This article revisits the electric, magnetic, and toroidal dipolar moments in metamaterial structure and presents a flatland design for generating a toroidal dipolar response. Through numerical analysis and electromagnetic multipole theory, it is found that the earlier symmetric unit cell design cannot produce a toroidal dipolar moment. A new planar metasurface design is proposed, which shows a higher scattered power and a dominant toroidal response when excited by a TM-polarized electromagnetic wave.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Physics, Multidisciplinary
Mircea Dolineanu, Amanda Teodora Preda, Dragos-Victor Anghel
Summary: The parity violation in nuclear reactions led to the discovery of a new class of toroidal multipoles. These toroidal multipoles have been observed in different systems, including elementary particles, solid state systems, and metamaterials. In this study, we analyze a quantum particle in a system with cylindrical symmetry, where toroidal moments are commonly found. We derive the expressions for the Hamiltonian, momenta, and toroidal dipole operators, and explore the properties of these operators in different coordinate systems. Additionally, we numerically diagonalize the Hamiltonian and toroidal dipole operator to obtain their eigenfunctions and eigenvalues. Moreover, we discuss the potential applications of these systems in the development of metamaterials that utilize the quantization and quantum properties of toroidal dipoles.
PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Haishen Zhang, Chengyao Zhang, Shuai Zhang, Yuhan Liu
Summary: Recently, terahertz metamaterials based on perovskite have gained attention due to their unique optical properties. A planar metamaterial consisting of split-ring resonators (SRRs) and perovskite has been proposed to transition from toroidal dipolar to electric dipole at terahertz frequency. The strong association between perovskite and the planar metamaterial allows for dynamic tuning of the transmission amplitude of toroidal dipolar resonance, potentially leading to applications such as tunable terahertz lasers and terahertz polarizers.
INTEGRATED FERROELECTRICS
(2021)
Article
Physics, Applied
Bo Sun, Yingying Yu, Hong Wang, Hongyu Zhu, Wenxing Yang
Summary: This study focuses on exciting anti-parallel aligned toroidal dipole arrays in metamaterials and regulating the total energy by producing an antiparallel coupling effect between the toroidal dipoles. Numerical and experimental analyses were conducted on the coupling of toroidal moments in metamaterials. The results show that the geometric parameters of the period play significant roles in altering the resonance response, and when the intensities of two opposite dipoles are similar, the toroidal interaction energy reaches a maximum, increasing the total energy and Q-factor.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Engineering, Electrical & Electronic
Xuanru Zhang, Tie Jun Cui
Summary: The study introduces a novel toroidal plasmonic resonator that tightly compacts all resonance modes and reduces radiation loss, achieving a high quality factor. A trapped mode is excited by introducing a slit perturbation, doubling the confinement effect. The on-chip excitation of the trapped mode is analyzed, showing good agreement between experimental results and numerical simulations.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Multidisciplinary Sciences
Sae June Park, Robyn Tucker, Emma Pickwell-MacPherson, John E. Cunningham
Summary: Finite element method simulations are used to investigate the response of terahertz split-ring resonators integrated with on-chip terahertz waveguides to cancerous tissues. The transmission spectra of the integrated system are obtained for different tissue states, and it is found that resonant frequency shift can be used to distinguish cancerous and healthy tissues. The electric field distribution and magnitude near the resonators are investigated for different gap widths, and simulated imaging shows the potential application of the technique in distinguishing tumor margins.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Materials Science, Multidisciplinary
Pengfei Shi, Yangyang Cao, Hongge Zhao, Renjing Gao, Shutian Liu
Summary: In this paper, a desktop wireless power transmission (DWPT) implementation method based on parallel-strips-coupled split ring resonators (PSSRR) is proposed for efficient long-distance wireless charging and to overcome the irregularity of the transmission path. The PSSRR, consisting of split ring resonators, dielectric disks, and parallel conductor strips, allows for effective conversion between magnetic field and propagating mode through near field magnetic resonance coupling. Simulation and experimental results demonstrate the feasibility and robustness of the proposed method, achieving a transmission efficiency of 76% at a distance of 1900 mm under a plane bent path.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Chemistry, Analytical
Cameron Rohan, Jacques Audet, Adrian Keating
Summary: This study explores the use of split-ring resonator (SRR) designs to create a planar antenna that addresses potential issues associated with protruding antennas, achieving successful designs for operation at LoRa frequencies while considering the impact of geometrical and physical tolerances.
Article
Physics, Multidisciplinary
Dragos-Victor Anghel, Mircea Dolineanu
Summary: This study provides a new classical mechanical representation for describing the eigenstates of a particle confined in a thin film bent into a torus shape. These eigenstates do not belong to the Hilbert space of wave functions but can be interpreted as kernels of distributions in the formalism of rigged Hilbert spaces. Additionally, quantization rules for the eigenvalues are derived, which are crucial for describing measurements in quantum mechanics.
Article
Physics, Applied
Victor Dmitriev, Anton S. Kupriianov, Silvio Domingos Silva Santos, Vladimir R. Tuz
Summary: In this study, the conditions for excitation of symmetry-protected toroidal dipole modes in all-dielectric metasurfaces composed of trimer or twin-trimer clusters were discussed. Various methods were used to describe the characteristics of toroidal modes in the clusters, and theoretical results were validated through numerical simulations and experiments. The properties of the toroidal dipole modes in the metasurface are primarily determined by the parameters of a single cluster and are not a result of the periodicity of the array. Coupling of the toroidal dipole modes in the twin-trimers can appear in both bonding and anti-bonding fashion, resulting in different net toroidal dipole moment orders.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
