Article
Nanoscience & Nanotechnology
Yongzhi Cheng, Fu Chen, Hui Luo
Summary: This paper presents a plasmonic chiral metasurface absorber (CMSA) that achieves high selective absorption for right-handed and left-handed circular polarization lights at optical frequency. The CMSA shows strong circular dichroism effects with selective absorption peaks for RCP and LCP lights at different resonance frequencies, reaching absorption rates of 93.2% and 91.6% respectively. The chiroptical response mechanism is illustrated by electric fields distributions of the unit-cell nanostructure, and the influence of CMSA geometry on circular polarization selective absorption is systematically studied.
NANOSCALE RESEARCH LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Zeyu Feng, Chenlu He, Yifan Xie, Chutian Zhang, Jiahe Li, Dingdong Liu, Zifan Jiang, Xin Chen, Gang Zou
Summary: Chiral metal nanostructures have recently gained attention due to their strong chiroptical properties and enhanced light-matter interactions. In this study, twisted-stacked silver nanowire arrays (TNAs) with independently controllable CD signals at interband transition and plasmonic extinction regions were constructed. These TNAs exhibited high sensitivity towards protein secondary structures, with different responses depending on the protein's beta-sheets or alpha-helices content. The mutually independent optical activities at the interband transition and plasmonic extinction regions complemented each other, providing enhanced sensitivity and reliability in chiral biosensing.
Article
Chemistry, Multidisciplinary
Cuiping Ma, Peng Yu, Wenhao Wang, Yisong Zhu, Feng Lin, Jiaying Wang, Zhimin Jing, Xiang-Tian Kong, Peihang Li, Alexander O. Govorov, Dong Liu, Hongxing Xu, Zhiming Wang
Summary: This paper theoretically investigates the dynamics of thermally induced fluid convection of a chiral plasmonic metasurface and proposes the concept of optofluidic circular dichroism. Results show different fluid velocities of thermally induced convection around a chiral plasmonic metasurface under different circularly polarized excitation. This concept can potentially be used to induce chiral fluid convection in various optofluidics applications.
Article
Chemistry, Multidisciplinary
Peizhao Liu, Yann Battie, Yutaka Okazaki, Naoya Ryu, Emilie Pouget, Sylvain Nlate, Takashi Sagawa, Reiko Oda
Summary: Helical and twisted silica nanoribbons deposited on a quartz substrate exhibit chiral optical scattering, with the g-factor of helical nanoribbons being approximately 10(-2) below 250 nm. The signs of chiral optical scattering depend on the handedness of the nanohelices, and simulations using the boundary element method investigated the effect of helix morphology and orientation on the scattering.
CHEMICAL COMMUNICATIONS
(2021)
Article
Physics, Applied
Zhancheng Li, Yifan Jiang, Wenwei Liu, Yuebian Zhang, Hua Cheng, Junjie Li, Jianguo Tian, Shuqi Chen
Summary: We demonstrate that hybrid bilayer plasmonic metasurfaces, fabricated through a simple one-step nanofabrication process, are ideal candidates for realizing intrinsic chiral optical responses and spin-selective transmission. The proposed metasurfaces offer advantages such as compact design, easy control of chiral optical response, and lower fabrication demand, thus expanding the application potential of chiral plasmonic nanostructures in spin nanophotonics, nonlinear optics, and optical sensing.
APPLIED PHYSICS LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Chenglong Zheng, Jie Li, Guocui Wang, Jitao Li, Silei Wang, Mengyao Li, Hongliang Zhao, Zhen Yue, Yating Zhang, Yan Zhang, Jianquan Yao
Summary: Metamaterials achieve superior electromagnetic properties by adjusting structure, and chiral metamaterials are widely used in optics. A novel approach using all-silicon coding metasurfaces to achieve chirality-like function through spin decoupling is proposed, with experimental verifications conducted.
Article
Optics
Min Zhang, Danni Hao, Shuai Wang, Rui Li, Shou Wang, Yanqing Ma, Ramiro Moro, Lei Ma
Summary: This paper reports a subwavelength chiral metamaterial structure with tunable geometries and compositions for chiral biochemical sample detection. The chiroptical response of the metamaterial can be adjusted by manipulating the number of stacking layers and the twisted angle of the periodic unit. Experimental and numerical analysis reveal that the chiroptical response originates from the optical resonances of the gold disks and the adjacent array layers. The chiral metamaterial can achieve label-free detection of proline in biological samples and enantio-discrimination of chiral molecules, and the transmission circular dichroism (TCD) intensity can be regulated by the analyte concentration.
Article
Materials Science, Multidisciplinary
K. Chang, Z. Zheng, J. E. Sipe, J. L. Cheng
Summary: This paper theoretically studies the optical activity in a doped system and derives the optical activity tensor from a light wave vector dependent linear optical conductivity. The obtained expression for the optical activity tensor is in good numerical agreement with a recent theory for an undoped topologically trivial gapped system. The theory is applied to the optical activity of a gated twisted bilayer graphene, with a detailed discussion of the dependence on various factors.
Article
Physics, Applied
Ying Cui, Xiaosai Wang, Huan Jiang, Yongyuan Jiang
Summary: In this paper, we demonstrated high-efficiency and tunable circular dichroism (CD) using a symmetry broken graphene-dielectric-metal composite microstructure. The introduction of slot patterns in graphene ribbons leads to giant polarization-selective absorption for circularly polarized wave excitations, and the operating frequency and magnitude of CD can be dynamically controlled by gating graphene's Fermi energies.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Optics
He Wang, Zhe Qin, Lingling Huang, Yongfeng Li, Ruizhe Zhao, Hongqiang Zhou, Haoyang He, Jieqiu Zhang, Shaobo Qu
Summary: In this paper, a generic strategy based on dynamic chiral meta-atom is proposed for achieving strong circular dichroism and applicable electromagnetic functionality. Feasibility is demonstrated through numerical simulation and experimental verification. The proposed strategy is expected to broaden the horizon for dynamic chiral meta-devices and find applications in information encryption, anti-counterfeiting, and other dynamic systems.
Article
Chemistry, Multidisciplinary
Jiajia Chen, Xieyu Chen, Zhen Tian
Summary: This work presents a new strategy for the development of tunable terahertz chiral devices by studying a switchable chiral metasurface. The metasurface, based on a phase change material, can switch between left-handed and right-handed circularly polarized mirrors and find applications in polarization-dependent fields.
APPLIED SCIENCES-BASEL
(2022)
Article
Nanoscience & Nanotechnology
Rui Wang, Chenqian Wang, Ti Sun, Xin Hu, Chinhua Wang
Summary: In this study, a novel approach using a two-dimensional all-dielectric chiral metasurface is proposed to achieve simultaneous broadband and high circular dichroism (CD) with high polarization extinction ratio (PER) in the optical communication band. Theoretical and experimental results show that a CD of 0.9 and a PER exceeding 20 dB can be achieved in the wavelength range of 1.39 to 1.61 μm. This research paves the way for practical applications of chiral metasurfaces in various fields.
Article
Optics
Xiangkai Zeng, Daniel Rosenmann, David A. Czaplewski, Jie Gao, Xiaodong Yang
Summary: In this study, a mid-infrared chiral metasurface absorber with strong chiroptical effects and circular dichroism responses is designed and demonstrated. The absorption rate and CD value can be tuned by varying the geometric parameters of the metasurface, and a strong correlation between CD in absorption and temperature difference is observed.
OPTICS COMMUNICATIONS
(2022)
Article
Optics
Xiaona Yan, Ran Wang, Weimeng Luan, Xinzhuo Gao, Zuanming Jin, Guohong Ma
Summary: A chiral metamaterial made of bilayer twisted split-ring resonators is proposed to achieve tunable, dual-directional, and multifunctional polarization conversion for terahertz waves. Simulations show that different types of polarization conversion can be achieved by adjusting the polarization and propagating direction of the incident waves. The physical mechanisms of the converter are demonstrated by circular polarization transmission coefficients and surface current distribution.
Article
Biochemistry & Molecular Biology
Shoma Hirokawa, Nagao Kobayashi, Soji Shimizu
Summary: The study elaborates inherently chiral subporphyrins by forming a fused pyran ring at the periphery, showing that the chiroptical properties can be controlled by peripheral substitution and meso-aryl substituents. The circular dichroism (CD) properties of chiral subporphyrins are largely affected by the peripheral substituents and the dihedral angles between the meso-aryl substituents and the subporphyrin core.
Article
Materials Science, Multidisciplinary
Dongru Yang, Yongzhi Cheng, Fu Chen, Hui Luo, Ling Wu
Summary: In this paper, a broadband reflective metasurface (MS) with patterned graphene is proposed and numerically investigated for wavefront manipulation in the terahertz (THz) region. The unit-cell of the proposed reflective MS consists of a dielectric substrate, a single layer oval-hollow-structure (OHS) graphene, and a metal ground-plane, enabling cross-polarization conversion of circularly polarized (CP) waves in reflection mode. By changing the orientation angle of the OHS graphene, full 2 pi phase shifts of the reflected orthogonal CP wave can be achieved over a broadband frequency range with different Fermi energy levels (EF). Furthermore, the efficiency of reflection CP conversion is highly dependent on EF variation. Particularly, the efficiency of anomalous reflection and focusing effect of the reflective MS can be dynamically adjusted by changing EF. It has great prospects in THz applications such as communication and imaging.
DIAMOND AND RELATED MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Yongzhi Cheng, Yingjie Qian, Hui Luo, Fu Chen, Zhengze Cheng
Summary: In this paper, a narrowband perfect metasurface absorber (MSA) based on a micro-ring-shaped GaAs array was proposed and theoretically investigated in the terahertz (THz) region for enhanced refractive index (RI) sensing. Simulation results showed that the proposed perfect MSA achieved an absorbance of 99.9% at 2.213 THz with a Q-factor of approximately 460.08, which was efficiently confirmed by the coupling mode theory (CMT). The perfect absorption of the designed structure was primarily contributed by the guided mode of critical resonance coupling. The absorption properties of the proposed structure could be adjusted by changing the geometrical parameters of the GaAs structure. The proposed MSA, due to its higher Q-factor, can enhance RI sensing applications with a sensitivity of about 1.45 THz/RIU. This research provides a new approach for constructing highly efficient MSAs with potential applications in sensing, detecting, and imaging in the THz region.
PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES
(2023)
Article
Engineering, Electrical & Electronic
Zimu Zhang, Yongzhi Cheng, Hui Luo, Fu Chen
Summary: This paper proposes a wideband circular polarization metasurface antenna, consisting of a centrosymmetric structure with a mode suppressor and an asymmetric aperture-coupled feed structure separated by dielectric substrates. Two orthogonal modes with a 90 degrees phase difference are excited by an L-shaped slot and a microstrip line in the aperture-coupled feed structure to achieve CP radiation. Two methods are proposed to expand the CP bandwidth: directly suppressing the characteristic mode and indirectly suppressing it using a mode suppressor. The fabricated antenna shows a low profile of ?(0) x ?(0) x 0.075 ?(0) at 5 GHz, with a 3 dB axial ratio bandwidth of 45.2% (4.1-6.5 GHz), an impedance bandwidth of 41.8% (4.1-6.31 GHz), and a peak gain of 7.94 dBic at 5.9 GHz.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2023)
Article
Chemistry, Physical
Beibei Ma, Fu Chen, Yongzhi Cheng, Xian Wang, Shuoqing Yan, Rongzhou Gong, Hui Luo
Summary: In this study, Ti3C2Tx MXene@NiFe-layered double hydroxide (NiFe-LDH) derived multi-interfacial FeNi3/TiN@nitrogen-doped carbon (NC)@magnetic multiwalled carbon nanotube composites were prepared using a hydrothermal process and subsequent carbothermal reduction. The phase compositions, morphology, defects, and electromagnetic parameters of the composites can be adjusted by the thermal treatment temperature. The composites exhibit high reflection loss and effective absorption bandwidth, making them promising microwave absorption materials.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Multidisciplinary
Zhixiang Xu, Cheng Ni, Yongzhi Cheng, Linhui Dong, Ling Wu
Summary: In this paper, a photo-excited metasurface (MS) based on hybrid patterned photoconductive silicon (Si) structures is proposed to achieve tunable reflective circular polarization (CP) conversion and beam deflection at two frequencies independently in the terahertz (THz) region. The proposed MS consists of a metal circular-ring (CR), Si ellipse-shaped-patch (ESP), and circular-double-split-ring (CDSR) structure, a middle dielectric substrate, and a bottom metal ground plane. By modifying the conductivity of the Si ESP and CDSR components through external infrared-beam pumping power, the proposed MS can achieve high efficiency reflective CP conversion and 2π phase shift at two distinct frequencies. A supercell MS is also constructed for reflective CP beam deflection with dynamically tunable efficiency. The proposed MS shows promising applications in active functional THz wavefront devices.
Article
Multidisciplinary Sciences
Dongru Yang, Yongzhi Cheng, Hui Luo, Fu Chen, Ling Wu
Summary: This paper presents a simple design of an ultrathin and ultra-broadband single-layer metamaterial surface (MS) based on a double-arrow-shaped resonator (DASR) structure for both transmission and reflection modes in the terahertz (THz) region. The single-layer MS consists of a periodic array of metal DASRs and complementary circular patches (CCPs) on a thin dielectric substrate. Numerical results show that the MS structure can convert circularly polarized (CP) waves to their orthogonal components after reflection and transmission simultaneously, with an average amplitude of approximately 0.45 from 0.45 to 1.75 THz and a relative bandwidth of 118.2%. The CP conversion efficiency is close to the theoretical limit of 25% for single-layer structures. Additionally, by adjusting the orientation angle (alpha) of the DASR structure along the wave propagation direction, 0-2 pi phase shifts for the reflected and transmitted orthogonal CP waves can be achieved simultaneously. Numerical simulations demonstrate wave beam deflection, vortex beam generation, and focusing effects for both reflection and transmission modes. This design offers new possibilities and potential for developing multifunctional full-space devices.
ADVANCED THEORY AND SIMULATIONS
(2023)
Article
Engineering, Electrical & Electronic
Yongzhi Cheng, Yingjie Qian, Haruki Homma, Ashif Aminulloh Fathnan, Hiroki Wakatsuchi
Summary: In this study, two types of waveform-selective microwave metasurface absorbers (MMAs) were numerically and experimentally demonstrated. By designing specific circuit and geometrical parameters, these absorbers can selectively absorb signals of specific waveforms at the same frequencies, including higher-order modes. These waveform-selective MMAs have a wide range of applications in electromagnetic shielding, detection, sensing, and wireless communications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Chemistry, Physical
Fu Chen, Yongzhi Cheng, Xiangcheng Li, Hui Luo
Summary: This study successfully prepared 2D Ti3CNTx-based magnetic composites by modifying Ti3CNTx nanomaterials and combining them with magnetic materials, achieving broadband microwave absorption. The microwave absorption properties of the composites were investigated by varying the volume ratio of the nanomaterials and the filling ratio of the absorber. With a thickness of 1.32 mm, the absorber achieved a bandwidth of 4.75 GHz. Integrated with a macroscale multilayer periodic gradient design, the metastructure based on FCM (Fe@NC/Ti3CNTx) composites achieved broadband microwave absorption with an EAB of 12.5 GHz ranging from 5.5 GHz to 18 GHz at a total thickness of 4.5 mm. The microwave attenuation mechanisms were studied through dielectric loss, magnetic loss, and impedance matching. The multi-scale development of MXene-based magnetic composites enables their potential application in broadband microwave absorption.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Sihai Lv, Yongzhi Cheng, Fu Chen, Xiangcheng Li, Hui Luo
Summary: This study proposes the incorporation of manganese oxide into carbon matrix magnetic composites to enhance the electromagnetic wave (EMW) absorption properties. Multiple interfacial ternary-component Fe3C/MnO/Nitrogen-doped carbon (NC) absorbers were synthesized through facile hydrothermal, oxidative polymerization, and carbothermal reduction processes. The designed composites exhibit excellent EMW absorption properties, with an effective absorption bandwidth of 4.88 GHz (13.12-18 GHz) at a mere thickness of 1.5 mm. The outstanding performance of EMW absorption can be attributed to effective modulation of electromagnetic parameters through a large number of heterogeneous interfaces, defects, and magnetic loss. Meanwhile, adjusting the filling ratios of the composites in the absorber can significantly adjust the electromagnetic parameters of the samples. This work presents an effective approach for the preparation of high-performance EMW absorbers with ternary components, as well as a strategy for developing novel broadband absorbers that are lightweight and have thin thickness.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Automation & Control Systems
Mingkang Long, Qing An, Housheng Su, Hui Luo, Jin Zhao
Summary: In this work, the consensus issues of discrete-time multi-agent systems with completely unknown dynamic are investigated using reinforcement learning technique. A value iteration based model-free algorithm is proposed for consensus of these systems with optimal performance. To implement the algorithm without information of dynamics, actor-critic networks are constructed to estimate the value functions and optimal control inputs in real time. Simulation results verify the validity of the proposed algorithm.
JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS
(2023)
Article
Materials Science, Multidisciplinary
Linhui Dong, Yongzhi Cheng, Hui Luo, Fu Chen, Xiangcheng Li
Summary: This paper proposes an all-metal metasurface that enables circular polarization conversion and wavefront manipulation of terahertz waves. Numerical simulations demonstrate high transmission and reflection conversion coefficients over a wide frequency range, as well as the ability to achieve 2 pi-phase full coverage. The study also showcases the multifunctional wavefront manipulation capabilities of the proposed metasurface.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Jiaao Yu, Hui Luo, Zhihui Wang, Sihai Lv, Yongzhi Cheng, Fu Chen, Shuoqing Yan, Xiangcheng Li
Summary: By adjusting the thermal treatment temperatures, magnetic N-doped carbon foams with diverse surface morphologies were synthesized, and their microstructure, electromagnetic parameters, and microwave absorption properties could be tailored. The results showed that the composites exhibited exceptional microwave absorption properties and reduction of the far-field radar cross section (RCS).
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Physics, Applied
Hiroki Takeshita, Daisuke Nita, Yongzhi Cheng, Ashif Aminulloh Fathnan, Hiroki Wakatsuchi
Summary: In this study, a design method for waveform-selective metasurface absorbers operating in multiple frequency bands is presented and validated through numerical and experimental verification. The method allows the absorbers to preferentially absorb target electromagnetic waves of the same frequency based on the incident waveform, specifically the pulse width. By adjusting the spatial ratio of unit cells assigned to different frequencies, the performance of the dual-band approach is enhanced. This study opens up possibilities for the utilization of waveform-selective metasurfaces in diverse frequency bands, providing a valuable and versatile solution for various applications.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Tinggui Chen, Baizhan Xia, Dejie Yu, Chuanxing Bi
Summary: This study proposes a gradient phononic crystal structure for enhanced acoustic sensing. By breaking the symmetry of the PC structure, topologically protected edge states are introduced, resulting in topological acoustic rainbow trapping. The robustness and enhancement properties are verified numerically and experimentally.
