- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- 2015
- periodic paperclip-shaped structure
- antenna array
- mutual coupling reduction
- Bessel Function
- Coupling Coefficient
- Fusion temperature and Elongation speed
- Electronic Science and Technology
- Physics
- UIN Suska Riau
- Xi'an University of the Science and Technology
- University of Riau
-
-shaped chiral metamaterials
摘要： A highly sensitive refractive index sensor based on the conjugated bilayer-shaped chiral metamaterial is proposed. It is composed of two-shaped structures and a microstrip connecting line. The strong conductive coupling between two-shaped structures can be realized by microstrip connecting line. The chiral metamaterial shows giant circular dichroism (CD) effect, and the CD effect can up to 93.8% and 96.2% at 1.767Thz and 3.008Thz, respectively. The physical origin of the observed CD effect is elucidated through distributions of magnetic and current at resonances. The designed conjugated bilayer-shaped chiral metamaterial as a refractive index sensor can achieve sensitivity of 1.065Thz/RIU and 1.777Thz/RIU, respectively. The effect of structural parameter on the sensitivity and CD spectra is investigated. Through this study we presented the giant CD metamaterial based on conductive coupling and its application potentials for low detection-limit physical and biochemical sensing applications.
关键词： chiral metamaterial,conductive coupling,circular dichroism,resonance,refractive index sensor,metamaterial
更新于2025-09-23 15:22:29
-
Conductive Fused Porphyrin Tapes on Sensitive Substrates by a Chemical Vapor Deposition Approach
摘要： Oxidative polymerization of nickel(II) 5,15-diphenyl porphyrin and nickel(II) 5,15-bis(di-3,5-tert-butylphenyl) porphyrin by an oxidative chemical vapor deposition (oCVD) approach yields multiply fused porphyrin oligomers in thin film form. The oCVD technique enables the formation, deposition and p-doping of conjugated poly(porphyrins) coatings in a single step without the use of solvents or post-treatments. The decisive reactions and side reactions during the oCVD process are evidenced by high-resolution mass spectrometry. Due to the highly conjugated structure of the fused porphyrin tapes the thin films exhibit an electrical conductivity of 3.6×10–2 S·cm–1 and strong absorption in the visible to near-infrared spectral region. The formation of smooth conjugated poly(porphyrins) thin films, even on sensitive substrates, is demonstrated by their successful deposition and patterning on glass, silicon and printer paper. The ability to form conductive poly(porphyrins) thin films could enable the design of a new category of optoelectronic devices using the oCVD approach.
关键词： Chemical Vapor Deposition,Polymerization,Oxidative Coupling,Porphyrins,Thin Films
更新于2025-09-23 15:22:29
-
[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - A Technique to Suppress Mutual Coupling in Densely Packed Antenna Arrays Using Metamaterial Supersubstrate
摘要： A simple and practical technique for reducing the mutual coupling between neighbouring antennas is presented for application in densely packed antenna arrays. This is achieved by locating between the radiation elements a smaller patch with metamaterial decoupling structure (MTM-DS). In this case the radiating elements are circular patches and the MTM-DS is constructed from a hexagonal slit resonator. The consequence of implementing the MTM-DS patch is significant reduction in mutual coupling between adjacent radiating patches by 60%, improvement in impedance match by 200% and substantial increase in the antenna’s fractional bandwidth by 369%. Since the ground plane is unaltered the front-to-back ratio is unaffected too. The proposed technique is easily realizable and can be used effectively in beam scanning applications.
关键词： phased antenna arrays,metamaterial,Mutual coupling,microstrip antennas,beam scanning
更新于2025-09-23 15:22:29
-
Resonant inelastic x-ray incarnation of Young’s double-slit experiment
摘要： Young’s archetypal double-slit experiment forms the basis for modern diffraction techniques: The elastic scattering of waves yields an interference pattern that captures the real-space structure. Here, we report on an inelastic incarnation of Young’s experiment and demonstrate that resonant inelastic x-ray scattering (RIXS) measures interference patterns, which reveal the symmetry and character of electronic excited states in the same way as elastic scattering does for the ground state. A prototypical example is provided by the quasi-molecular electronic structure of insulating Ba3CeIr2O9 with structural Ir dimers and strong spin-orbit coupling. The double “slits” in this resonant experiment are the highly localized core levels of the two Ir atoms within a dimer. The clear double-slit-type sinusoidal interference patterns that we observe allow us to characterize the electronic excitations, demonstrating the power of RIXS interferometry to unravel the electronic structure of solids containing, e.g., dimers, trimers, ladders, or other superstructures.
关键词： Resonant inelastic x-ray scattering,quasi-molecular orbitals,electronic excitations,Young's double-slit experiment,spin-orbit coupling,interference patterns
更新于2025-09-23 15:22:29
-
Disentangling Coupling Effects in the Infrared Spectra of Liquid Water
摘要： A quantitative characterization of intermolecular and intramolecular couplings that modulate the OH-stretch vibrational band in liquid water has so far remained elusive. Here, we take up this challenge by combining the centroid molecular dynamics (CMD) formalism, which accounts for nuclear quantum effects, with the MB-pol potential energy function, which accurately reproduces the properties of water across all phases, to model the infrared (IR) spectra of various isotopic water solutions with different levels of vibrational couplings, including those that cannot be probed experimentally. Analysis of the different IR OH-stretch lineshapes provides direct evidence for the partially quantum-mechanical nature of hydrogen bonds in liquid water, which is emphasized by synergistic effects associated with intermolecular coupling and many-body electrostatic interactions. Furthermore, we quantitatively demonstrate that intramolecular coupling, which results in Fermi resonances due to the mixing between HOH-bend overtones and OH-stretch fundamentals, are responsible for the shoulder located at ～3250 cm?1 of the IR OH-stretch band of liquid water.
关键词： liquid water,nuclear quantum effects,infrared spectra,Fermi resonances,centroid molecular dynamics,hydrogen bonds,intramolecular coupling,intermolecular coupling,MB-pol potential energy function
更新于2025-09-23 15:21:21
-
Intense red emission and two-way energy transfer in Sm3+, Eu3+ co-doped NaLa(WO4)2 phosphors
摘要： NaLa(WO4)2 phosphors with various Eu3+ and Sm3+ concentrations were prepared via a molten salt method. The structure and luminescent properties of the prepared samples were analyzed by the X-ray diffraction (XRD) and fluorescence spectrophotometer. The results show that the crystal phase of all the prepared samples is single tetragonal crystal structure. The energy transfer type between Eu3+ ions is proved to be the exchange interaction and the electron-phonon coupling is weak. With the increase of the Sm3+ concentration, the energy transfer from Sm3+ to Eu3+ in NaLa(WO4)2:0.15Eu3+,xSm3+ is transformed from Eu3+ to Sm3+, and the mechanism for energy transfer is given.
关键词： Nanophosphor powders NaLa(WO4)2: xEu3+ ySm3+,Electron-phonon coupling,Photoluminescence,Energy transfer
更新于2025-09-23 15:21:21
-
Finite-time Stückelberg interferometry with nanomechanical modes
摘要： Stückelberg interferometry describes the interference of two strongly coupled modes during a double passage through an avoided energy level crossing. In this work, we investigate finite-time effects in Stückelberg interferometry and discuss the exact analytical solution of the double passage Stückelberg problem by expanding the finite-time solution of the Landau–Zener problem. Approximating the return probability amplitudes of the double passage in distinct limits reveals uncharted parameter regimes of Stückelberg interferometry where finite-time effects affect the coherent exchange of energy. We find the long-time limit of the exact solution to formally coincide with the well-established adiabatic impulse model which is, to the best of our knowledge, the only regime of Stückelberg interferometry reported so far. Experimentally, we study all predicted regimes using a purely classical, strongly coupled nanomechanical two-mode system of high quality factor. The classical two-mode system consists of the in-plane and out-of-plane fundamental flexural mode of a high stress silicon nitride string resonator, coupled via electric gradient fields. We exploit our experimental and theoretical findings by studying the onset of Stückelberg interference in dependence of the characteristic system control parameters and obtain characteristic excitation oscillations between the two modes even without the explicit need of traversing the avoided crossing. The presented findings are not limited to classical mechanical two-mode systems but can be applied to every strongly coupled (quantum) two-level system, for example a spin-1/2 system or superconducting qubit.
关键词： strong coupling,nanoelectromechanical systems,finite times,Stückelberg interferometry
更新于2025-09-23 15:21:21
-
Collective strong light-matter coupling in hierarchical microcavity-plasmon-exciton systems
摘要： Polaritons are compositional light-matter quasiparticles that arise as a result of strong coupling between the vacuum field of a resonant optical cavity and electronic excitations in quantum emitters. Reaching such a regime is often hard, as it requires materials possessing high oscillator strengths to interact with the relevant optical mode. Two-dimensional transition metal dichalcogenides (TMDCs) have recently emerged as promising candidates for realization of strong coupling regime at room temperature. However, these materials typically provide coupling strengths in the range of 10-40 meV, which may be insufficient for reaching strong coupling with low quality factor resonators. Here, we demonstrate a universal scheme that allows a straightforward realization of strong coupling with 2D materials and beyond. By intermixing plasmonic excitations in nanoparticle arrays with excitons in a WS2 monolayer inside a resonant metallic microcavity, we fabricate a hierarchical system with the collective microcavity-plasmon-exciton Rabi splitting exceeding ~500 meV at room temperature. Photoluminescence measurements of the coupled systems show dominant emission from the lower polariton branch, indicating the participation of excitons in the coupling process. Strong coupling has been recently suggested to affect numerous optical- and material-related properties including chemical reactivity, exciton transport and optical nonlinearities. With the universal scheme presented here, strong coupling across a wide spectral range is within easy reach and therefore exploring these exciting phenomena can be further pursued in a much broader class of materials.
关键词： TMDC,Strong plasmon-exciton coupling,collective Rabi splitting,monolayer WS2
更新于2025-09-23 15:21:21
-
Simple molecular-engineering approach for enhancing orientation and out-coupling efficiency of thermally activated delayed fluorescent emitters without red-shifting emission
摘要： The inclusion of a tetraphenylbenzene (4Ph) unit in thermally activated delayed fluorescence (TADF) emitters is demonstrated as a novel strategy for greatly enhancing the horizontally oriented alignment of the emitters without shifting the emission spectrum to longer wavelengths. Doping of blue-emitting 4PhOXDDMAC or greenish-blue-emitting 4PhOXDPXZ into o-DiCbzBz host layers yielded much higher degrees of horizontally oriented alignment for the emitter (up to 92%) compared to when the 4Ph unit was excluded (69% and 75%, respectively). The enhanced alignment results in high out-coupling efficiencies of 24% and 35% in organic light-emitting diodes based on 4PhOXDDMAC and 4PhOXDPXZ, respectively, and boosts the external quantum efficiencies to values (8.8% and 29.2%, respectively) that are higher than would be expected for randomly oriented emitters (out-coupling efficiency of 20%). These enhancements are achieved while avoiding the red-shift that often occurs using the common strategy of increasing molecular length, and, thereby, conjugation, to increase orientation.
关键词： transition dipole moment,thermally activated delayed fluorescence,light out-coupling factor,molecular orientation,organic light-emitting diodes
更新于2025-09-23 15:21:21
-
Potential Dependence of Mechanical Stability and Electronic Coupling of Single S-Au Bonds
摘要： Providing a mechanically stable and electronically efficient coupling between a molecule and an electrode is critical to the study of charge transfer and conductance of the molecule. A common method is to link the molecule to Au electrodes via a linker (e.g., thiol terminal of the molecule). Here we study the mechanical stability and electronic coupling of S-Au bond in single molecule junctions over a broad range of electrode potential. Our results show that the mechanical and electromechanical properties of molecule-electrode contact undergo a systematic change with the potential involving Au oxidation at positive potentials and S protonation at negative potentials. The study establishes the potential range for a stable S-Au bond and determines the potential dependence of the mechanical and electromechanical properties of the molecule-electrode contact, which is crucial to the interpretation of potential dependent charge transfer in electrochemistry and electrochemical gating of charge transport in molecular electronics.
关键词： molecule-electrode contact,electronic coupling,electrode potential,S-Au bond,mechanical stability
更新于2025-09-23 15:21:21