Transverse Effects Research Articles

Self-powered high-performance photo and thermal detectors based on the transverse thermoelectric effect of the inclined La-doped BiCuSeO films

Transverse thermoelectric (TTE) effect of the inclined thin films has attracted great attention owing to the application in self-powered photo and thermal detectors. Here, we report the significant enhancement of TTE performance of the inclined BiCuSeO thin films via La doping. The maximum voltage sensitivity of the La-doped BiCuSeO TTE detector reaches about 15.7 V/mJ under the ultraviolet pulsed laser irradiation, which is more than 17 times larger than that of the intrinsic BiCuSeO thin film. Besides, the detector also exhibits good linearity, long-term stability, ultra-broad spectral detection ability as well as the excellent thermal detection performance, with the voltage sensitivity is much higher than that of commercial Gordon gauge. The results show that La doping can effectively improve the TTE performance of the inclined BiCuSeO thin films, which has a prospect and potential application in self-powered high-performance photo and thermal detectors.

Light-induced transverse thermoelectric effect in MOCVD-deposited La1−xSrxMnO3 (0.08 ≤ x ≤ 0.7) thin films with inclined structure

Light-induced transverse thermoelectric effect in MOCVD-deposited La1−xSrxMnO3 (0.08 ≤ x ≤ 0.7) thin films with inclined structure

Transverse magnetic field effects on the high-voltage pulsed discharge plasma in helium

This study investigates the effect of a transverse magnetic field on high-voltage pulsed discharge in helium at a pressure of 30 Torr. A simple two-dimensional fluid model that describes the high-voltage pulsed discharge in helium in a transverse weak magnetic field (B = 0.4 T) is presented, which uses an empirical relation to account for the magnetic field. The results of using the empirical relation for the effective field agree well with the experimental results. The dynamics of discharge development in the presence of the magnetic field is also investigated. The magnetic field does not significantly affect the gas-discharge development dynamics in helium at a pressure of 30 Torr.

Transverse Magneto-Optical Kerr Effect Enhancement in Si–Ni Nanogratings by Mie and Surface Lattice Resonances

Transverse Magneto-Optical Kerr Effect Enhancement in Si–Ni Nanogratings by Mie and Surface Lattice Resonances

Enhancement in the magneto-optical effect induced by combining multiple modes in a gold film–supported hybrid periodic gold/magnetic nanorod array

In this study, the possibility of enhanced transverse magneto-optical Kerr effect (TMOKE) and performance monitoring of a hybrid nanostructure developed by sandwiching a ferromagnetic film within a gold layer and square periodic nanorod arrays, is theoretically investigated. Based on the findings, the TMOKE signal can be enhanced approximately 33 times when compared to the referenced planar film, which is elucidated by the hybrid of modes in the magnetic film region. In addition, a high level of environmental sensor performance is simultaneously achieved by recording the wavelength resonance positions with the variation of refractive index, which is compatible with gaseous medium from 1 to 1.01, indicating that the structure of the proposal will have applications in environmental monitoring.

Dynamic response of a large-diameter end-bearing pile in permafrost

Vertically dynamic model of a large-diameter pile in frozen soil is established, in which the frozen soil is described to a saturated frozen porous media, and the large diameter end-bearing pile is simplified to a one-dimensional rod considering the influence of the transverse inertia effect. Analytical solutions of the longitudinal coupling vibration between the end-bearing pile and the frozen soil are obtained using Helmholtz decomposition and variable separation methods in the frequency domain. By comparing the dynamic responses of the longitudinal vibration of the large diameter end-bearing pile with the traditionally one-dimensional pile, as well as the impedance factor of the frozen soil layer induced by the pile vibration, these demonstrate the influence of the transverse inertia effect on the high frequency vibration of large diameter pile is significant, and the influence on the pile with a smaller slenderness ratio is larger. The temperature and the Poisson’s ratio also have significant effects on the vertical vibration of large diameter piles in frozen soil, which cannot be ignored in the analysis.

The growth mechanism and properties of Bi2212 thin films on miscut substrates by sol-gel method

A sol-gel methodology is employed to prepare Bi2212 thin films on single crystal LaAlO3 miscut substrates with nominal tilt angles of 0°, 5°, 10°, and 15°. The study focuses on examining the phase purity, crystal structure, surface morphology, microstructure, and properties of these thin films. Experimental results indicate that the growth of Bi2212 thin films on miscut substrates proceeds through the step-flow mode using the sol-gel method. Higher tilt angles lead to an increase in the conventional resistivity of Bi2212 thin films. Tilted Bi2212 thin films exhibit a typical transverse Seebeck effect when comparing the resistivity in different directions. Notably, the Seebeck coefficient difference reaches 12 V/K when the substrate tilt angle is set at 15°. Meanwhile, tilted Bi2212 thin films consistently exhibit outstanding superconducting transition temperature (Tc) while demonstrating lower critical current density (Jc) values. These findings offer valuable insights for the development of Bi2212 high temperature superconducting thin films (HTSFs) in thermoelectric and superconductive devices, serving as a reference point for achieving optimal film characteristics.

Theoretical analysis of radiation effects in laminar flow over a von-Kármán body of revolution

An analysis presents the impact of thermal radiation on the laminar boundary layer established due to the motion of a von-Kármán surface. The reason for choosing such a shape is its appearance in many aeronautical vehicles, especially the F-16 fighter jet nose cone. However, the transverse curvature effects are also observable in many other shapes of bodies of revolution. But considering such a practical body of revolution provides a chance to quantify the transport phenomena happening on sophisticated aerospace vehicles. As a result, a correct understanding of the momentum and the thermal process in actual situations can be achieved. Power-law form of wall temperature is assumed to cover a variety of non-isothermal wall conditions. The typical body contour of a von-Kármán surface does not allow the scaling symmetry in the longitudinal direction; thus making the flow of non-similar in nature. An efficient numerical scheme (Keller–Box) with the second order accuracy is used for the solution purposes. The results are found to be satisfactory regarding the previous published work for moving cylinder cases. This ensures the validity of the tabulated data for the von-Kármán surface case. Through numerous tables and graphs, the impacts of thermal radiation parameter, wall temperature exponent, and transverse curvature parameter have been highlighted and thoroughly analyzed. Once the radiation parameter is increased, it is noticed that the rate of heat transfer increases and the thermal thickness of the boundary layer grows, whereas the reverse behavior is seen when the wall temperature exponent is increased. Furthermore, it has been found that increasing the surface transverse curvature increases the thermal thickness of the boundary layer and the rate of heat transfer. To the considered body shape, the reported data are expected to serve as a good source for the development of approximate methods concerning complex flow geometries involving transverse curvature effects.

Enhanced Sensitivity of Magneto-Optical Surface Plasmon Resonance in the FeCu Superlattices

We demonstrated the sensitivity enhancement for magneto-optical surface plasmon resonance (MOSPR) using noble/ferromagnetic metals multilayers. The proposed structure is based on the Kretschmann configuration in the transverse magneto-optical Kerr effect (TMOKE) methods with the FeCu superlattices (SLs) as magneto-plasmonic materials and gelatin as biomolecules analyte. The dielectric constants of the FeCu SLs are taken from first principles calculation, which is performed by using a full-potential linearized augmented plane wave (FLAPW) method. The important role of the hybridization process in optical transitions has been identified, and it can be modulated by adjusting the thickness of superlattices. The dependence of the reflectivity on the dielectric constant is performed by 4×4 transfer matrix methods. It is found that the minimum reflectivity directly influences the slope of angular spectra, with a maximum slope of TMOKE signal is 12.23/degree. The change in the gelatin’s refractive index results in TMOKE signal response, then the enhancement of the sensitivity of the MOSPR system can be shown.

Revisiting physical mechanism of longitudinal photonic spin splitting and Goos-Hänchen shift

The intrinsic connection between the transverse photonic spin Hall effect (PSHE) and the Imbert–Fedorov shift has been well characterized. However, physical insights into the longitudinal photonic spin splitting associated with the Goos-Hänchen (GH) shift remain elusive. This paper aims to expand the theory of the PSHE generation mechanism from the transverse to the longitudinal case by examining the reflection of each spin component from an arbitrarily linearly polarized incident Gaussian beam on the air-dielectric interface. Unlike the transverse case, both spin-maintained and spin-flipped modes exhibit non-zero longitudinal displacements, with the latter being affected by the second-order expansion term of the Fresnel reflection coefficient with respect to the in-plane wave-vector component. Meanwhile, the polarization angle plays a crucial role in determining the longitudinal PSHE since each reflected total spin component is a coherent superposition of these two corresponding modes. Remarkably, the imaginary part of the relative permittivity of the dielectric significantly affects the symmetry of the longitudinal PSHE. Furthermore, the GH shift results from a superposition of individual spin states’ longitudinal displacements, taking into account their energy weights. By incorporating the corresponding extrinsic orbital angular momentum, we explore the generation mechanism of the symmetric/asymmetric longitudinal PSHE. The unified physical framework elucidating the longitudinal photonic spin splitting and GH shift provides a comprehensive understanding of the fundamental origin of the PSHE and beam shifts, paving the way for potential applications in spin-controlled nanophotonics.

On transverse crack effects in beams under free vibration using finite element analysis

The research attempt towards quantifying the free vibration frequencies for cracked uniform isotropic beam through finite element analysis for analyzing the crack effects is discussed in this investigation. The present approach involves dividing the beam into segments at the crack section, which were modelled for simulation for eigen frequencies on ABAQUS platform. The simulation model is developed considering a C3D8R element. The segments are then joined together by considering interaction forces through flexibility matrices. These matrices are resulted from the compliance matrix that is governed using expressions of release rate of strains considering the stress intensity factors as described in fracture mechanics. Within the equal domain of analysis for a comparison, the findings align remarkably well with previous research, affirming the reliability, effectiveness and precision of the proposed simulation model. By examining the results of present numerical simulations, an understanding towards how the crack magnitude in depth and position affects the mode shape and frequencies of the cracked beams is elicited. This study solidifies the application suitability of developed simulation model for effective analysis of beam-like structural components.

Giant longitudinal and transverse magnetothermoelectric effects in a van del Waals semimetal TaCo2Te2

TaCo2Te2 exhibits giant longitudinal and transverse magneto-thermoelectric effects, suggesting its great potential for thermoelectric refrigeration applications.

A third-order shear deformation plate bending formulation for thick plates: first principles derivation and applications

A third-order shear deformation plate bending formulation is presented in this study from the first principles. The derivation assumed a displacement field constructed using third-order polynomial function of the transverse (z) coordinate; and made to apriori satisfy the linear three-dimensional (3D) kinematics relations as well as the transverse shear stress free boundary conditions at the top and bottom plate surfaces. The formulation thus has no need for shear stress correction factors of the first-order shear deformation plate theories. The domain equations of equilibrium are obtained as a set of three coupled differential equations in terms of three unknown displacements. The system of coupled equations is solved for simply supported rectangular and square plates subjected to four cases of loading distributions: sinusoidal loading, uniformly distributed loading, linearly distributed loading and point load at the plate center. Navier’s double trigonometric series method is used to construct trial solutions for the three displacement functions such that the boundary conditions are satisfied identically. The integration problem is thus reduced to an algebraic problem and is solved for each considered loading. It is found that the present formulation gives exact results for the normal stresses σxx for sinusoidal and uniformly distributed loads. The study further showed that the results for deflection and stresses agreed with Krishna Murty’s higher order shear deformation plate theory results. The present formulation gave accurate results because of the inclusion of transverse normal strain effects in the formulation. The formulation gives a quadratic variation of the transverse shear stresses across the thickness in consonance with the theory of elasticity method.

Strong transverse magneto-optical Kerr effect at normal incidence based on hybrid bound states in the continuum

Strong transverse magneto-optical Kerr effect at normal incidence based on hybrid bound states in the continuum

Dissipative light bullets in a doped and weakly nonlocal optical fiber

The letter introduces an extended (3+1)-dimensional [(3+1)D] nonlocal cubic complex Ginzburg-Landau equation describing the dynamics of dissipative light bullets in optical fiber amplifiers under the interplay between dopants and a spatially nonlocal nonlinear response. The model equation includes the effects of fiber dispersion, linear gain, nonlinear loss, fiber nonlinearity, atomic detuning, linear and nonlinear diffractive transverse effects, and nonlocal nonlinear response. A system of coupled ordinary differential equations for the amplitude, temporal, and spatial pulse widths and position of the pulse maximum, unequal wavefront curvatures, chirp parameters, and phase shift is derived using the variational technique. A stability criterion is established, where a domain of dissipative parameters for stable steady-state solutions is found. Direct integration of the proposed nonlocal evolution equation is performed, which allows us to investigate the evolution of the Gaussian beam along a doped nonlocal optical fiber, showing stable self-organized dissipative spatiotemporal light bullets.

A wide dynamic range diamond quantum sensor as an electric vehicle battery monitor.

To demonstrate the application capability of the diamond quantum sensor as an electric vehicle (EV) battery monitor, we (i) investigated the measurable current in a real car noise level and (ii) compared the linearity with conventional sensors. Consequently, (i) we could measure a 20 mA current pulse even under an external magnetic field of 80 µT, which is larger than that of 50 µT around the EV battery module in a real car during driving. The 20 mA pulse measurement corresponds to the EV battery state of charge estimation accuracy of 0.2% in the standard driving pattern, which is smaller than the present level of 10%. (ii) The linearity degradation seen in the Hall sensor near the upper limit of the measurement range was not seen in the diamond sensor. Although the Hall sensor and the shunt resistor showed linearity degradation in the current range of several tens of amperes or less, the degradation was smaller for the diamond sensor. The transverse magnetic field effect in the diamond sensor on the linearity was estimated to be less than 0.01% for a several-degree misalignment of the sensor surface to the magnetic field direction and under a 340 A current. This article is part of the Theo Murphy meeting issue 'Diamond for quantum applications'.

A modified spring-mass model of low-velocity-impact on composite laminate including shearing deformation at delaminated region and reduction on membrane stiffness

A modified spring-mass model for response prediction of composite laminate subjected to destructive large mass impact was developed based on perturbation analysis on membrane stiffness and modified subsection superposition of bending stiffness. The reduction of the membrane effect caused by impact induced intraply matrix failure was evaluated by substituting the perturbated elastic modulus into the membrane stiffness. The subsection superposition method for calculating the bending stiffness of delamination-damaged laminate was modified by considering the transverse shear effect. According to the results of the finite element simulation, the accuracy of the first-order shear deformation theory (FSDT)-based subsection superposition method in evaluating the bending stiffness of delaminated laminates is obviously higher than the classical plate theory (CPT)-based one with the increase of laminate thickness. Destructive drop weight impact tests on the FRP laminate were conducted to validate the proposed model. The results show that the FSDT-based model is more accurate than the CPT-based one in destructive large mass impact response analysis.

Inclined ITO thin film with thermoelectric anisotropy: A promising sensitivity material for ultraviolet pulsed photodetector based on light-induced transverse voltage effect

Indium tin oxide (ITO) thin film, a typical transparent conductive oxide, is usually used as a material for thin film thermocouples due to its large Seebeck coefficient and low resistivity. In this work, inclined epitaxial ITO thin films have been prepared on c-axis miscut YSZ (001) single crystal substrates. The distinct response voltages, oriented perpendicular to the temperature gradient, are detected based on the light-induced transverse voltage (LITV) effect, originating from the anisotropic Seebeck coefficient ΔS between the ab-plane and c-axis of ITO thin films. Following the high-temperature annealing process, ITO thin films experience a significant increase in ΔS by an order of magnitude, thereby amplifying the response voltage. The voltage amplitudes have a good linear relationship with the inclined angles (sin2α). Moreover, under the irradiation of a 248 nm pulsed laser, the response voltage exhibited a fast response time with a rise time τr of 20∼26 ns and decay time τd of 18∼24 ns due to the intrinsic characteristic of low resistivity, demonstrating its potential to be a candidate material for fast response self-powered ultraviolet photodetector.

Evidences of thermoelectrically driven unidirectional magnetoresistance from a single Weyl ferromagnet Co2MnGa

Weyl ferromagnets, with large anomalous Hall (and Nernst) effects, are an ideal playground to study unconventional transport phenomena. Here, we report a sizable unidirectional magnetoresistance with a ratio of up to 7.73 × 10−5 per current density of 1 MA cm−2 in single-layer epitaxial Co2MnGa films. Surprisingly, the nonlinear signal has an isotropic crystallographic axis dependence and scales almost linearly with the film thickness. Both features cannot be explained by the spin transport from an intrinsic band structure, but rather agree with the current induced transverse thermoelectric effect. By employing a 1D heat transfer model to account for the temperature gradient, we derived an analytical expression of this thermoelectrically driven unidirectional magnetoresistance, from which a upper bound of transverse thermopower Sxy = 3.70 ± 1.10 µV K−1 can be obtained. Our work provides direct evidences of thermoelectric voltages in the nonlinear transport signals that may be extended to other material systems as well.

A Simple Application of a Trigonometric Inequality to the Relativistic Doppler Effect

In recent years, the special theory of relativity (SR) has been included in high school curricula in almost all countries. In addition to the classic demonstrations of the relativity of time and lengths, another interesting relativistic phenomenon that is shown, is the transverse Doppler effect. Obviously it is not possible to rigorously prove, at the high school level, the final relation but, from it, we have analyzed some physical consequences using trigonometry. In this paper, which has a didactic aim, we summarize one of our lessons held during some of the in-depth lectures on relativity that we often organize for high school students in our area.