Terahertz polarization devices are an important part of terahertz optical systems. Traditional terahertz polarization devices rely on birefringent crystals, and their performances are limited by the material structures. In this work, we theoretically demonstrate that the metamaterial consisting of the medium and the periodic metal band embedded in the medium can control broadband polarization effectively

The dynamics of produced excited carriers under the irradiation of Ge crystal is investigated theoretically by using femtosecond laser pulse. A two-temperature model combined with the Drude model is also used to study the nonequilibrium carrier density, carrier and lattice temperatures, and optical properties of the crystal. The properties of the surface plasmon wave when excited are also studied.

In this paper, we propose a theoretical model of the surface plasmon resonance-based optical fiber biosensor for detecting glucose concentration. The Au/ZnO/WS 2 multilayer film is coated around optical fiber. Compared with the conventional surface plasmon resonance sensor, WS 2 material can increase the sensitivity of the biosensor. The absorption capacity of WS 2 is used to load glucose oxidase by

Si/a-C:H(Ag) multilayer films with different modulation periods are prepared to test their potential applications in human body. The composition, microstructure, mechanical and tribological properties in the simulated body fluid are investigated. The results show the concentration of Ag first decreases and then increases with the modulation period decreasing from 984 nm to 250 nm. Whereas the C content

The diamond-like cubic silicon (d-Si) is widely used in modern electronics and solar cell industries. However, it is not an optimal candidate for thermoelectric application due to its high lattice thermal conductivity. Si (oP32) is a recently predicted orthorhombic silicon allotrope, whose total energy is close to that of d-Si. Using first-principles calculations and Boltzmann transport theory, we

We investigate the local quantum uncertainty (LQU ) in weak measurement. An expression of weak LQU is explicitly determined. Also, we consider some cases of three special X states, Werner state, circulant two-qubit states, and Heisenberg model via LQU in normal and weak measurements. We find that the LQU in weak measurement is weaker than the case of strong measurement.

The physical process of a single-stage planar-pulsed-inductive accelerator is investigated. Measurements include the waveforms of circuit current, capacitor voltage, plasma radiation intensity, and temporal plasma structure photos captured by a high-speed camera. Experiments are conducted under static ambient fill condition using argon as propellant. Varied values of capacitor voltage and gas pressure

We apply the heat jet approach to realize atomic simulations at finite temperature for a Frenkel–Kontorova chain with moving dislocation. This approach accurately and efficiently controls the system temperature by injecting thermal fluctuations into the system from its boundaries, without modifying the governing equations for the interior domain. This guarantees the dislocation propagating in the atomic

The sintering–alloying processes of nickel (Ni), iron (Fe), and magnesium (Mg) with aluminum (Al) nanoparticles were studied by molecular dynamics simulation with the analytic embedded-atom model (AEAM) potential. Potential energy, mean heterogeneous coordination number ##IMG## [http://ej.iop.org/images/1674-1056/29/11/116601/cpb_29_11_116601_ieqn1.gif] {${N}_{{\rm{A}}}^{{\rm{B}}}$} , and surface atomic

A general solution is obtained to a canonical problem of the reflection and refraction of an arbitrary shaped beam by using a uniaxially anisotropic chiral slab. The reflected, internal as well as refracted shaped beams are expanded in terms of cylindrical vector wave functions, and the expansion coefficients are determined by using the boundary conditions and method of moments procedure. As two typical

Systematic error suppression and test data processing are very important in improving the accuracy and sensitivity of the atom interferometer (AI)-based weak-equivalence-principle (WEP) test in space. Here we present a spectrum correlation method to investigate the test data of the AI-based WEP test in space by analyzing the characteristics of systematic errors and noises. The power spectrum of the

EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices, and the doped one could be a good spin injector. Herein, we fabricate a spin-functional tunnel junction by epitaxially growing the ferromagnetic EuS film on Nb-doped SrTiO 3 . The improvement of Curie temperature up to 35 K is associated with indirect exchange through additional charge carriers at the interface

Spin Hall nano oscillator (SHNO), a new type spintronic nano-device, can electrically excite and control spin waves in both nanoscale magnetic metals and insulators with low damping by the spin current due to spin Hall effect and interfacial Rashba effect. Several spin-wave modes have been excited successfully and investigated substantially in SHNOs based on dozens of different ferromagnetic/nonmagnetic

Na 0.5 Bi 0.5 TiO 3 –BiMnO 3 (NBT–BM) limited solid solution films were fabricated to investigate the lattice modification on the energy storage performances. The introduction of the BM solute lattice induces the NBT solvent lattices undergoing the transition from the pure phase, solid solution, solubility limit to precipitation. Correspondingly, the polarization states transfer from the macroscopic

The memristor is a kind of non-linear element with memory function, which can be applied to chaotic systems to increase signal randomness and complexity. In this paper, a new four-dimensional hyper-chaotic system is designed based on a flux controlled memristor model, which can generate complex chaotic attractors. The basic dynamic theory analysis and numerical simulations of the system, such as the

Effects of initial surface termination on electrical characteristics of La 2 O 3 /Al 2 O 3 nanolaminates deposited by atomic layer deposition are studied by conductive atomic force microscopy working in contact mode and standard electrical characterization methods. It is found that, compared with La 2 O 3 /Al 2 O 3 nanolaminates with LaO x as termination, lower interface trap density, less current

We investigate the ground-state phases and spin textures of spin–orbit-coupled dipolar pseudo-spin-1/2 Bose–Einstein condensates in a rotating two-dimensional toroidal potential. The combined effects of dipole–dipole interaction (DDI), spin–orbit coupling (SOC), rotation, and interatomic interactions on the ground-state structures and topological defects of the system are analyzed systematically. For

We calculate the spin and density susceptibility of Weyl fermions with repulsive S-wave interaction in ultracold gases. Weyl fermions have a linear dispersion, which is qualitatively different from the parabolic dispersion of conventional materials. We find that there are different collective modes for the different strengths of repulsive interaction by solving the poles equations of the susceptibility

A two-SBT-memristor-based chaotic circuit was proposed. The stability of the equilibrium point was studied by theoretical analysis. The close dependence of the circuit dynamic characteristics on its initial conditions and circuit parameters was investigated by utilizing Lyapunov exponents spectra, bifurcation diagrams, phase diagrams, and Poincaré maps. The analysis showed that the circuit system had

The formation of nanoscale water capillary bridges (WCBs) between chemically heterogeneous (patchy) surfaces plays an important role in different scientific and engineering applications, including nanolithography, colloidal aggregation, and bioinspired adhesion. However, the properties of WCB of nanoscale dimensions remain unclear. Using molecular dynamics simulations, we investigate the geometrical

We investigate the modulation of magnetic anisotropy of thulium iron garnet (TmIG) films by interfaced Bi 2 Se 3 thin films. High quality epitaxial growth of Bi 2 Se 3 films has been achieved by molecular beam epitaxy on TmIG films. By the method of ferromagnetic resonance, we find that the perpendicular magnetic anisotropy (PMA) of TmIG can be greatly strengthened by the adjacent Bi 2 Se 3 layer.

Smart textiles responding to the ambient environment like temperature, humidity, and light are highly desirable to improve the comfortability and realize multifunctions. The bamboo yarn has merits like air permeability, biodegradability, and excellent heat dissipation performance, but it has not been prepared for responsive materials and smart textiles. In this paper, the moisture-responsive twisted

We train a neural network to identify impurities in the experimental images obtained by the scanning tunneling microscope (STM) measurements. The neural network is first trained with a large number of simulated data and then the trained neural network is applied to identify a set of experimental images taken at different voltages. We use the convolutional neural network to extract features from the

The influence of transition metals (Sc, Ti, V, Cr, and Mn) doping at different distances on the magnetism of CdS is studied by using generalized gradient approximation combined with Hubbard U in the VASP package. The results show that the doping systems are more stable, easy to form, and the wurtzite structure of CdS is not changed. It is found that the systems are antiferromagnetic (AFM) when nearest

Corresponding to the atmospheric transmission windows of the electromagnetic spectrum in the low terahertz range, the mode coupling and dispersion characteristics of two helically corrugated waveguides (HCW) in the frequency ranges of 90 GHz–100 GHz and 260 GHz–265 GHz are studied. Through analytic calculations and numerical simulations, dispersion curves and structural parameters of the two frequency

We review the recent discoveries of exotic phenomena in graphene, especially superconductivity. It has been theoretically suggested for more than one decade that superconductivity may emerge in doped graphene-based materials. For single-layer pristine graphene, there are theoretical predictions that spin-singlet d + id pairing superconductivity is present when the filling is around the Dirac point

The electronic and thermoelectric properties of alkali metal-based fluorides CsYbF 3 and RbYbF 3 are studied by using Wien2k and BoltzTraP codes. The structural and thermodynamic stability of these materials are confirmed by tolerance factor (0.94 and 0.99 for RbYbF 3 and CsYbF 3 ) and negative formation energy. The optimized lattice constants and bulk moduli are consistent with the results reported

In this work, we report the reorientation of magnetization by spin–orbit torque (SOT) in YIG/Pt bilayers. The SOT is investigated by measuring the spin Hall magnetoresistance (SMR), which is highly sensitive to the direction of magnetic moment of YIG. An external in-plane rotating magnetic field which is applied to the YIG/Pt bilayers, and the evolutions of SMR under different injected currents in

We demonstrate an all-fiberized narrow-linewidth nanosecond amplifier with high peak power, tunable pulse width, and repetition rate. A fiber-coupled narrow-linewidth laser diode operating at 1064.1 nm is employed as the seed source, which is gain-switched to generate nanosecond pulses with tunable pulse widths of 1–200 ns and tunable repetition rates of 10 Hz–100 kHz. By utilizing a very-large-mode-area

Theoretical investigation on the propagation characteristics of a new class of laser beams known as multi Gaussian (M.G) laser beams has been presented. To investigate the linear characteristics, propagation of the laser beam in vacuum has been considered. Whereas, the nonlinear characteristics have been investigated in plasmas. Optical nonlinearity of the plasma has been modeled by relativistic mass

The manipulating of optical waves in a microcavity is essential to developing the integrated optical devices. Generally, the two eigenmodes in a whispering-gallery-mode (WGM) microcavity possess chiral symmetry. Here we show the chiral symmetry breaking is induced by the asymmetric backscattering of counter-propagating optical waves in a whispering-gallery-mode (WGM) microcavity with a cavity-made

Traditional materials discovery is in ‘trial-and-error’ mode, leading to the issues of low-efficiency, high-cost, and unsustainability in materials design. Meanwhile, numerous experimental and computational trials accumulate enormous quantities of data with multi-dimensionality and complexity, which might bury critical ‘structure–properties’ rules yet unfortunately not well explored. Machine learning

We report an approach of high-pressure hydrogenation to improve the performance of crystalline Si (c-Si) solar cells. As-received p-type c-Si wafer-based PN junctions were subjected to high-pressure (2.5 MPa) hydrogen atmosphere at 200 °C, followed by evaporating antireflection layers, passivation layers, and front and rear electrodes. The efficiency of the so prepared c-Si solar cell was found to

The decentralized fuzzy inference method (DFIM) is employed as an optimization technique to reconstruct time- and space-dependent heat flux of two-dimensional (2D) participating medium. The forward coupled radiative and conductive heat transfer problem is solved by a combination of finite volume method and discrete ordinate method. The reconstruction task is formulated as an inverse problem, and the

Based on the quantum technique of the weak measurement and quantum measurement reversal (WMR), we propose a scheme to protect entanglement for an entangled two-qubit pure state from four typical quantum noise channels with memory, i.e. , the amplitude damping channel, the phase damping channel, the bit flip channel, and the depolarizing channel. For a given initial state | ψ 〉 = a | 00 〉 + d | 11 〉

A new efficient two-party semi-quantum key agreement protocol is proposed with high-dimensional single-particle states. Different from the previous semi-quantum key agreement protocols based on the two-level quantum system, the propounded protocol makes use of the advantage of the high-dimensional quantum system, which possesses higher efficiency and better robustness against eavesdropping. Besides

We design an actively tunable polarization-sensitive multiband absorber in the mid-infrared region, which consists of stacked graphene multilayers separated by dielectric layers on a metal mirror. Benefiting from the anisotropic structure, the absorber has dual absorption bands with almost perfect absorption at different wavelengths under the x and y polarizations. Analyzing the electric field amplitude

We study a two-dimensional quantum walk with only one walker alternatively walking along the horizontal and vertical directions driven by a single two-side coin. We find the analytical expressions of the first two moments of the walker’s position distribution in the long-time limit, which indicates that the variance of the position distribution grows quadratically with walking steps, showing a ballistic

Complexity and abundant dynamics may arise in locally-active systems only, in which locally-active elements are essential to amplify infinitesimal fluctuation signals and maintain oscillating. It has been recently found that some memristors may act as locally-active elements under suitable biasing. A number of important engineering applications would benefit from locally-active memristors. The aim

The ionization dynamics of two-electron atom in an intense laser field is studied by the Bohmian mechanics (BM) theory, and the xenon atomic potential function is used as a model. The single ionization process and double ionization process are calculated by the BM theory and their results are in good agreement with those calculated by numerically solving the time-dependent Schrödinger equation. The

In the past decades there have been many breakthroughs in low-dimensional materials, especially in two-dimensional (2D) atomically thin crystals like graphene. As structural analogues of graphene but with a sizeable band gap, monolayers of atomically thin transition metal dichalcogenides (with formula of MX 2 , M = Mo, W; X = S, Se, Te, etc.) have emerged as the ideal 2D prototypes for exploring fundamentals

A fully developed electromagnetohydrodynamic (EMHD) flow through a microchannel with patterned hydrodynamic slippage on the channel wall is studied. The flow is driven by the Lorentz force which originates from the interaction between an externally imposed lateral electric field and a perpendicular magnetic field. The governing equations for the velocity with patterned slip boundary conditions are

Complex magnetically insulated transmission line oscillator (MILO), as an important development direction, can enhance the power efficiency and generate dual-band high power microwaves (HPMs). A complex MILO and a preliminary dual-band radiation system have been proposed in our previous studies. However, the axial length of the dual-band radiation system is too long to meet the compact requirements

We analytically and numerically investigate the dynamical properties of the tilted dispersion relativistic quasiparticles emerged in a cold atomic optical lattice system. By introducing the next nearest neighboring (NNN) hopping term into Su–Schrieffer–Heeger (SSH) model, the Dirac quasiparticles with tilted dispersion relation are realized. The results show that the tilted dispersion causes a drift

Tensile behaviors of Ti/Ni nanolaminate with model-I crack are investigated by molecular dynamics simulations. The Ti/Ni nanolaminates with center crack either in Ti layer or in Ni layer under different loading directions are utilized to systematically study the mechanical performance of the cracked material. The results indicate that pre-existing crack dramatically changes the plastic deformation

Designing tunable molecular devices with different charge carriers in single-molecule junctions is crucial to the next-generation electronic technology. Recently, it has been demonstrated that the type of charge carriers depends on and can be tuned by controlling the molecular length and the number of interfacial covalent bonds. In this study, we show that the type of charge carriers can also be tuned

We report the hydrothermal growth of pure and doped TiO 2 nanoparticles with different concentrations of carbon. The microstructure of the as-synthesized samples is characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy (EDX), and Raman spectroscopy to understand the structure and composition. The XRD patterns confirm the

Persistent photoconductivity (PPC) effect and its light-intensity dependence of both enhancement and depletion (E-/D-) mode amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) are systematically investigated. Density of oxygen vacancy (V O ) defects of E-mode TFTs is relatively small, in which formation of the photo-induced metastable defects is thermally activated, and the activation energy (

In cluster science, it is challenging to identify the ground state structures (GSS) of gold (Au) clusters. Among different search approaches, first-principles method based on density functional theory (DFT) is the most reliable one with high precision. However, as the cluster size increases, it requires more expensive computational cost and becomes impracticable. In this paper, we have developed an

The magneto–mechanical coupling effect and magnetic anisotropy of Fe 10 Co 90 (FeCo) films deposited on silicon wafer (Si), flexible polyethylene terephthalate (PET), freestanding polydimethylsiloxane (PDMS), and pre-stretched 20% PDMS substrates were studied in detail. The loop squareness ratio M r / M s and the coercive H c of the FeCo film grown on a PET substrate can be obviously tuned by applying

The detailed understanding of various underlying processes at liquid/solid interfaces requires the development of interface-sensitive and high-resolution experimental techniques with atomic precision. In this perspective, we review the recent advances in studying the liquid/solid interfaces at atomic level by electrochemical scanning tunneling microscope (EC-STM), non-contact atomic force microscopy

Water is ubiquitous and so is its presence in the proximity of surfaces. To determine and control the properties of interfacial water molecules at nanoscale is essential for its successful applications in environmental and energy-related fields. It is very challenging to explore the atomic structure and electronic properties of water under various conditions, especially at the surfaces. Here we review

The turbulence governed by the Navier–Stokes equation is paramount in many physical processes. However, it has been considered as a challenging problem due to its inherent nonlinearity, non-equilibrium, and complexity. Herein, we review the connections between the velocity derivative skewness S k and the non-equilibrium properties of turbulence. S k , a reasonable candidate for describing the non-equilibrium

We propose a two-dimensional metal grating with rhombus particles on a gold film structure for refractive index sensing due to its perfect absorption at near-infrared wavelength. Via two-dimensional metal grating coupling, the incident light energy is effectively transformed into the surface plasmons which propagate along the upper surface of the gold film and interact with the surrounding environment

The electronic properties of van der Waals (vdW) structures can be substantially modified by the moiré superlattice potential, which strongly depends on the twist angle among the compounds. In twisted bilayer graphene (TBG), two low-energy Van Hove singularities (VHSs) move closer with decreasing twist angles and finally become highly non-dispersive flat bands at the magic angle (∼ 1.1°). When the

We investigate the effect of impurities on the thermal entanglement in a spin-1/2 Ising–Heisenberg butterfly-shaped chain, where four interstitial Heisenberg spins are localized on the vertices of a rectangular plaquette in a unit block. By using the transfer-matrix approach, we numerically calculate the partition function and the reduced density matrix of this model. The bipartite thermal entanglement

Based on the framework of Kaniadakis’ statistics and its related kinetic theory, the Jeans instability for self-gravitational systems in the background of Eddington-inspired Born–Infield (EiBI) gravity is revisited. A dispersion relation generalizing the Jeans modes is derived by modifying the Maxwellian distribution to a family of power law distributions parameterized by the κ parameter. It is established

We investigate the alignment dependence of the strong laser dissociation dynamics of molecule ##IMG## [http://ej.iop.org/images/1674-1056/29/11/113202/cpb_29_11_113202_ieqn3.gif] {${{\rm{C}}}_{2}{{\rm{H}}}_{2}^{2+}$} in the frame of real-time and real-space time-dependent density function theory coupled with nonadiabatic quantum molecular dynamics (TDDFT-MD) simulation. This work is based on a recent

We study the ferromagnetic transition of a two-component homogeneous dipolar Fermi gas with 1D spin–orbit coupling (SOC) at finite temperature. The ferromagnetic transition temperature is obtained as functions of dipolar constant λ d , spin–orbit coupling constant λ SOC and contact interaction constant λ s . It increases monotonically with these three parameters. In the ferromagnetic phase, the Fermi

Passive filtering of neural networks with time-invariant delay and quantized output is considered. A criterion on the passivity of a filtering error system is proposed by means of the Lyapunov–Krasovskii functional and the Bessel–Legendre inequality. Based on the criterion, a design approach for desired passive filters is developed in terms of the feasible solution of a set of linear matrix inequalities