Integration of highly ordered plasmonic nanocavity array structure with the electrostatic driving force for dynamic control of SERS signals and label-free detection of λ-DNA.

With the rapid development of nanoscience and nanotechnology, surface-enhanced Raman spectroscopy (SERS) is widely used for the detection of analyte molecules and biomolecules in liquids. However, due to the plasmonic near-field effect, the key challenge of SERS detection in liquids is to attract target molecules in solutions into the plasmonic "hot spots". In this work, the SERS-active substrates (Ag@AAO) with excellent signal sensitivity and uniformity were successfully prepared by sputtering Ag films on anodized aluminum oxide (AAO) templates.

Enhanced trapping properties of coupled plasmonic tweezers via plasmon-exciton interaction.

Excited plasmonic nanoantennas enable the manipulation of photons coupled with quantum emitters or the trapping of particles as plasmonic tweezers, leveraging the strong evanescent gradient fields at the nanoscale. However, the ohmic loss of metals presents a significant challenge for the stable and high-precision manipulation of nanoparticles without causing damage. In this study, we investigated the enhanced trapping properties induced by plasmon-exciton interaction for coupled plasmonic tweezers.

Holographic Grating Enhancement Induced by a Dual-Photo-Initiator System in PMMA Substrate Polymers.

Polymer systems induced by the reaction between monomers and photo-initiators play a crucial role in the formation of volume-phase gratings. In this paper, we fabricated a dual-photo-initiator photopolymer by doping EY (Eosin Yellow) molecules into a TI (Titanocene, Irgacure 784@BASF) dispersed PMMA (poly-[methyl methacrylate]) substrate system, with the aim of promoting the diffusion and polymerization processes in volume holographic storage. The two-wave interference system is adopted to record a permanent grating structure in our materials.

Enhanced trapping properties induced by strong LSPR-exciton coupling in plasmonic tweezers.

Plasmonic tweezers break the diffraction limit and enable trap the deep-subwavelength particles. However, the innate scattering properties and the photothermal effect of metal nanoparticles pose challenges to their effective trapping and the non-damaging trapping of biomolecules. In this study, we investigate the enhanced trapping properties induced by strong coupling between localized surface plasmon resonances (LSPR) and excitons in plasmonic tweezers.

Dynamic Trapping and Manipulation of Self-Assembled Ag Nanoplates as Efficient Plasmonic Tweezers.

Plasmonic tweezers based on periodic nanostructures have been used to manipulate particles through multiple and uniform local surface plasmon (LSP) fields. However, the coverage area of periodic nanostructures is limited, which restricts the range of trapping and manipulation. In this paper, we present a novel approach to achieve large-scale manipulation and trapping of microspheres by uniformly coupled LSP fields on a short-range disordered self-assembled Ag nanoplates (DSNP) film.

Theoretical and Experimental Investigations of Diffraction Characteristics Influenced by Holographic Reciprocity Effect in PQ/PMMA Polymers.

We propose the holographic reciprocity effect (HRE) to describe the relationship between the exposure duration (ED) and the growth rate of diffraction efficiency (GRoDE) in volume holographic storage. The HRE process is investigated experimentally and theoretically in order to avoid the diffraction attenuation. Herein, introducing the medium absorption, we present a comprehensive probabilistic model to describe the HRE.

LSPR Tunable Ag@PDMS SERS Substrate for High Sensitivity and Uniformity Detection of Dye Molecules.

At present, the use of efficient and cost-effective methods to construct plasmonic surface-enhanced Raman scattering (SERS) substrates of high sensitivity, uniformity and reproducibility is still crucial to satisfy the practical application of SERS technology. In this paper, a localized surface plasmonic resonance (LSPR) tunable flexible Ag@PDMS substrate was successfully constructed by the low-cost bio-template-stripping method and magnetron sputtering technology. The theory proves that the local electromagnetic field enhancement and "hot spot" distribution is adjustable by modifying the size of the optical cavity unit in the periodicity nanocavity array structure.

Enhanced-wave pairing in the two-dimensional Hubbard model with periodically modulated hopping amplitudes.

Utilizing determinant quantum Monte Carlo algorithm, the evolution of the-wave pairing in the Hubbard model on the square lattice tuned by the periodically modulated hopping amplitudes is studied. The hopping amplitudes are homogeneous in thexˆ-direction, while in theyˆ-direction the hopping amplitudes are modulated with period, wherety=t+dt,ty'=t-(P-1)dt, and the modulation periodequals 2, 3 and 4 lattice spacings. The latter two modulation periods are motivated by the observation of period-3 and period-4 stripe order in cuprate superconductors.

Numerical study on a random plasmonic laser in the metal-insulator-metal structure.

This Letter proposes a random plasmonic laser in the metal-insulator-metal (MIM) structure, in which the dielectric core with gain is dispersed with circular dielectric nanoscatterers. The numerical results from finite-difference time-domain simulation indicate that scattering by the randomly distributed dielectric nanoscatterers in the MIM waveguide provides feedback to the random laser with surface plasmon. The design bypasses the requirement of a distributed feedback structure for the plasmonic waveguide-based nanolasers, which is challenging and expensive in fabrication.

Spontaneous n-Doping in Growing Monolayer MoS by Alkali Metal Compound-Promoted CVD.

Monolayer MoS has emerged as one of the most promising candidate materials for future semiconductor devices because of its fascinating physical properties and optoelectronic performance. Recently, the utilization of alkali metal compounds as promoters in CVD growth has been demonstrated to be a facile strategy for growing monolayer MoS and other 2D TMDs with large domain sizes. In this work, we systematically investigated the residues derived from alkali metal compounds and the spontaneous n-doping effect on monolayer MoS in alkali metal compound-promoted CVD growth.

Distinct ultrafast carrier dynamics of α-InSe and β-InSe: contributions from band filling and bandgap renormalization.

As an intrigued layered 2D semiconductor material, indium selenide (InSe) has attracted widespread attention due to its excellent properties. So far, the carrier dynamics of α-InSe and β-InSe are still lacking a comprehensive understanding, which is essential to enhancing the performance of InSe-based optoelectronic devices. In this study, we explored the ultrafast carrier dynamics in thin α-InSe and β-InSe transient absorption microscopy.

Reversible photoluminescence modulation of monolayer MoS on a ferroelectric substrate by light irradiation and thermal annealing.

Monolayer semiconducting two-dimensional (2D) materials are strongly emerging materials for exploring the spin-valley coupling effect and fabricating novel optoelectronic devices due to their unique structural symmetry and band structures. Due to their atomic thickness, their excitonic optical response is highly sensitive to the dielectric environment. In this work, we present a novel approach to reversibly modulate the optical properties of monolayer molybdenum disulfide (MoS) via changing the dielectric properties of the substrate by laser irradiation and thermal annealing.

Holographic Grating Enhancement of TI/PMMA Polymers in the Dark Diffusion Process.

The dark diffusion enhancement process (DDEP) caused by photopolymerization during the pre-exposure of TI/PMMA (titanocene dispersed methyl methacrylate matrix) polymers was theoretically analyzed and experimentally investigated, revealing the holographic grating enhancement of TI/PMMA polymers in the post-exposure process without additional operations. The diffusion of photo-initiators and photoproducts dominated the grating enhancement process after exposure. We adopted two pre-exposure methods, long-time (second level) and short-time (millisecond level) laser exposure, at 532 nm, to investigate the DDEP during the post-exposure process.

Quantum Monte Carlo study of the Hubbard model with next-nearest-neighbor hopping t': pairing and magnetism.

Using the finite-temperature determinant quantum Monte Carlo (DQMC) algorithm, we study the pairing symmetries of the Hubbard Hamiltonian with next-nearest-neighbor (NNN) hopping t' on square lattices. By varying the value of t', we find that the d-wave pairing is suppressed by the onset of t', while the p + ip-wave pairing tends to emerge for low electron density and t' around -0.7.

Electrically tunable polarization of random lasing from dye-doped nematic liquid crystals.

Tunable polarizing direction of random lasing emission by an applied electric field which radiated from the lateral end face of homogeneously aligned, dye-doped nematic liquid crystal (NLC) cell was demonstrated for the first time, to the best of our knowledge. The lasing emission was partially polarized in the direction along the director of the NLC without the applied electric field. By tuning the applied electric field, the NLC director could be rotated to arbitrary direction from homogeneous to homeotropic alignment, resulting in the polarizing direction of lasing emission to any direction from parallel to perpendicular to the substrate surface in the end face.

Impact of the pitch angle on the spin Hall effect of light weak measurement.

The spin Hall effect of light (SHEL), as a photonic analogue of the spin Hall effect, has been widely studied for manipulating spin-polarized photons and precision metrology. In this work, a physical model is established to reveal the impact of the interface pitch angle on the SHEL accompanied by the Imbert-Fedorov angular shift simultaneously. Then, a modified weak measurement technique is proposed in this case to amplify the spin shift experimentally, and the results agree well with the theoretical prediction.

Differential expression of microRNAs in tomato leaves treated with different light qualities.

Background: Light is the main source of energy and, as such, is one of the most important environmental factors for plant growth, morphogenesis, and other physiological responses. MicroRNAs (miRNAs) are endogenous non-coding RNAs that contain 21-24 nucleotides (nt) and play important roles in plant growth and development as well as stress responses. However, the role of miRNAs in the light response is less studied.

Holographic response characteristics influenced by an absorptive diffusion polymerization model in bulk TI/PMMAs.

Dynamic formation of a volume holographic grating is mainly caused by the diffusion polymerization of a photoinitiator in TI/poly-(methyl methacrylates) (PMMAs). Here, we consider the time-dependent absorption coefficient in this material to establish an absorption modulated diffusion polymerization model. An experimental and theoretical investigation in TI/PMMAs with different sample thicknesses (1-3 mm) is presented.

Porous Molybdenum Carbide Nanostructures Synthesized on Carbon Cloth by CVD for Efficient Hydrogen Production.

Molybdenum carbide (Mo C) is a promising noble-metal-free electrocatalyst for the hydrogen evolution reaction (HER), due to its structural and electronic merits, such as high conductivity, metallic band states and wide pH applicability. Here, a simple CVD process was developed for synthesis of a Mo C on carbon cloth (Mo C@CC) electrode with carbon cloth as carbon source and MoO as the Mo precursor. XRD, Raman, XPS and SEM results of Mo C@CC with different amounts of MoO and growth temperatures suggested a two-step synthetic mechanism, and porous Mo C nanostructures were obtained on carbon cloth with 50 mg MoO at 850 °C (Mo C-850(50)).

High efficiency active wavefront manipulation of spin photonics based on a graphene metasurface.

Metasurfaces have been widely studied for manipulating light fields. In this work, a novel metasurface element is achieved with a high circular polarization amplitude conversion efficiency of 88.5% that creates an opposite phase shift ranging from -180° to 180° between incidence and reflection for different spin components.

Ultrafast volume holographic recording with exposure reciprocity matching for TI/PMMAs application.

The range of exposure for which the holographic reciprocity law holds in photopolymers, is mainly dependent on the light exposure intensity and polymerization rate between photo-initiator and monomers. Matching this is the key to improving performance. Characterization of the dependence on diffraction efficiency of the volume transmission gratings on holographic reciprocity matching of TI/PMMAs under different milliseconds with different thickness (1-3mm) has been carried out for the novel high-sensitive TI/PMMA polymers.

Transcriptome Analysis of Low-Temperature-Induced Breaking of Garlic Aerial Bulb Dormancy.

The long history of asexual reproduction of garlic using garlic cloves has resulted in virus accumulation and genetic depression. Propagation of garlic seedlings by tissue culture can both eliminate viruses and improve breeding efficiency. Aerial bulbs are the first-choice materials for breeding virus-free garlic seedlings under external conditions, but they show dormancy just like garlic bulbs.

Comparative Transcriptome Analysis of Temperature-Induced Green Discoloration in Garlic.

Green discoloration is one of the most important problems that cause low quality of product in the processing of garlic, which can be induced by low-temperature stress. But the mechanism of low temperature-induced green discoloration is poorly understood. In the present study, the control garlic and three low temperature-treated garlic samples (stored at 4°C with 10, 15, and 40 days, respectively) were used for genome-wide transcriptome profiling analysis.