scholarly journals Interferometric imaging of nonlocal electromechanical power transduction in ferroelectric domains

2018 ◽  
Vol 115 (21) ◽  
pp. 5338-5342 ◽  
Author(s):  
Lu Zheng ◽  
Hui Dong ◽  
Xiaoyu Wu ◽  
Yen-Lin Huang ◽  
Wenbo Wang ◽  
...  
Keyword(s):  
Electric Fields ◽  
Elastic Waves ◽  
Near Field ◽  
Nanoelectromechanical Systems ◽  
Nonlocal Interaction ◽  
Interferometric Imaging ◽  
Displacement Fields ◽  
Domain Structures ◽  
Acoustic Wave Devices ◽  
Electrical Generation

The electrical generation and detection of elastic waves are the foundation for acoustoelectronic and acoustooptic systems. For surface acoustic wave devices, microelectromechanical/nanoelectromechanical systems, and phononic crystals, tailoring the spatial variation of material properties such as piezoelectric and elastic tensors may bring significant improvements to the system performance. Due to the much slower speed of sound than speed of light in solids, it is desirable to study various electroacoustic behaviors at the mesoscopic length scale. In this work, we demonstrate the interferometric imaging of electromechanical power transduction in ferroelectric lithium niobate domain structures by microwave impedance microscopy. In sharp contrast to the traditional standing-wave patterns caused by the superposition of counterpropagating waves, the constructive and destructive fringes in microwave dissipation images exhibit an intriguing one-wavelength periodicity. We show that such unusual interference patterns, which are fundamentally different from the acoustic displacement fields, stem from the nonlocal interaction between electric fields and elastic waves. The results are corroborated by numerical simulations taking into account the sign reversal of piezoelectric tensor in oppositely polarized domains. Our work paves ways to probe nanoscale electroacoustic phenomena in complex structures by near-field electromagnetic imaging.

Atomic 2D electric field imaging of a Yagi–Uda antenna near-field using a portable Rydberg-atom probe and measurement instrument

2020 ◽  
Vol 9 (5) ◽  
pp. 305-312
Author(s):  
Ryan Cardman ◽  
Luís F. Gonçalves ◽  
Rachel E. Sapiro ◽  
Georg Raithel ◽  
David A. Anderson
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Field Measurement ◽  
Near Field ◽  
Measurement Instrument ◽  
Rydberg Atom ◽  
Field Measurements ◽  
Atom Probe ◽  
Electric Field Measurement ◽  
Measurement Uncertainties

AbstractWe present electric field measurements and imaging of a Yagi–Uda antenna near-field using a Rydberg atom–based radio frequency electric field measurement instrument. The instrument uses electromagnetically induced transparency with Rydberg states of cesium atoms in a room-temperature vapor and off-resonant RF-field–induced Rydberg-level shifts for optical SI-traceable measurements of RF electric fields over a wide amplitude and frequency range. The electric field along the antenna boresight is measured using the atomic probe at a spatial resolution of ${\lambda }_{RF}/2$ with electric field measurement uncertainties below 5.5%, an improvement to RF measurement uncertainties provided by existing antenna standards.

Nonlinear nanoelectrodynamics of a Weyl metal

2021 ◽  
Vol 118 (48) ◽  
pp. e2116366118
Author(s):  
Yinming Shao ◽  
Ran Jing ◽  
Sang Hoon Chae ◽  
Chong Wang ◽  
Zhiyuan Sun ◽  
...  
Keyword(s):  
Electric Fields ◽  
Mirror Symmetry ◽  
Density Functional ◽  
Near Field ◽  
Surface States ◽  
Real Space ◽  
Resonance Structure ◽  
Nonlinear Conductivity ◽  
Weyl Semimetal ◽  
Photocurrent Spectroscopy

Chiral Weyl fermions with linear energy-momentum dispersion in the bulk accompanied by Fermi-arc states on the surfaces prompt a host of enticing optical effects. While new Weyl semimetal materials keep emerging, the available optical probes are limited. In particular, isolating bulk and surface electrodynamics in Weyl conductors remains a challenge. We devised an approach to the problem based on near-field photocurrent imaging at the nanoscale and applied this technique to a prototypical Weyl semimetal TaIrTe4. As a first step, we visualized nano-photocurrent patterns in real space and demonstrated their connection to bulk nonlinear conductivity tensors through extensive modeling augmented with density functional theory calculations. Notably, our nanoscale probe gives access to not only the in-plane but also the out-of-plane electric fields so that it is feasible to interrogate all allowed nonlinear tensors including those that remained dormant in conventional far-field optics. Surface- and bulk-related nonlinear contributions are distinguished through their “symmetry fingerprints” in the photocurrent maps. Robust photocurrents also appear at mirror-symmetry breaking edges of TaIrTe4 single crystals that we assign to nonlinear conductivity tensors forbidden in the bulk. Nano-photocurrent spectroscopy at the boundary reveals a strong resonance structure absent in the interior of the sample, providing evidence for elusive surface states.

Scattering of elastic waves near an explosion

1993 ◽  
Vol 83 (4) ◽  
pp. 1277-1293
Author(s):  
Donald Leavy
Keyword(s):  
Displacement Field ◽  
Elastic Waves ◽  
Near Field ◽  
Static Solution ◽  
Simple Relation ◽  
Perturbation Solution ◽  
First Order ◽  
Scattering Of Elastic Waves ◽  
Harmonic Decomposition ◽  
Complete Set

Abstract We use the method of small perturbation to study the scattered waves generated by an arbitrary 3D inhomogeneous medium around a spherically symmetric compressional source. We consider two models of the medium inside the source: a homogeneous solid and a fluid. The results from these two models differ only when scattering occurs within a few source's radii from the explosion. We find that there is a simple relation between the structure of the first order scattered waves and the structure of the medium, namely that a given harmonic of the medium parameters excites only the same harmonic of the two spheroidal potentials. When scattering occurs within a wavelength from the source, we find that the quadrantal terms in the spherical harmonic decomposition of the field have the lowest frequency dependence. They depend on frequency only through the spectrum of the source. Thus, in the far field, the dominant scattered waves generated near an explosion are similar to the primary waves generated by an earthquake. However, when the displacement field is observed in the near field of the explosion, the static solution reveals that a complete set of harmonics may be required to properly account for the displacement field. We compare the perturbation solution with the exact solution of the scattering by a sphere located within a wavelength from the source. This suggests that the perturbation solution has a fairly wide domain of practical applicability. We attempt to apply these results to the Love wave generated near the Boxcar nuclear explosion.

scholarly journals Broadband Plasmonic Nanopolarizer Based on Different Surface Plasmon Resonance Modes in a Silver Nanorod

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 447
Author(s):  
Junxi Zhang ◽  
Lei Hu ◽  
Zhijia Hu ◽  
Yongqing Wei ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Electric Fields ◽  
Near Infrared ◽  
Near Field ◽  
Resonant Cavity ◽  
Transverse Magnetic ◽  
Wave Mode ◽  
Fdtd Simulation ◽  
Nanophotonic Devices ◽  
Resonance Modes ◽  
Polarization Characteristics

Conventional polarizers including sheet, wire-grid, prism, and Brewster-angle type polarizers are not easily integrated with photonic circuits. Polarizing elements on the nanoscale are indispensable for integrated all-optical nanophotonic devices. Here, we propose a plasmonic nanopolarizer based on a silver nanorod. The polarization characteristics result from the excitation of different resonance modes of localized surface plasmons (LSPs) at different wavelengths. Furthermore, the polarization characteristics in near field regions have been demonstrated by the electric field distribution of the nanorod based on finite-difference time-domain (FDTD) simulation, indicating a strong local resonant cavity with a standing wave mode for transverse electric (TE) polarization and weak electric fields distributed for transverse magnetic (TM) polarization. The nanopolarizer can efficiently work in the near field region, exhibiting a nanopolarization effect. In addition, very high extinction ratios and extremely low insertion losses can be achieved. Particularly, the nanopolarizer can work in a broadband from visible to near-infrared wavelengths, which can be tuned by changing the aspect ratio of the nanorod. The plasmonic nanopolarizer is a promising candidate for potential applications in the integration of nanophotonic devices and circuits.

Convergence analysis in near-field imaging for elastic waves

2015 ◽  
Vol 95 (11) ◽  
pp. 2339-2360
Author(s):  
Peijun Li ◽  
Yuliang Wang ◽  
Yue Zhao
Keyword(s):  
Convergence Analysis ◽  
Elastic Waves ◽  
Near Field ◽  
Near Field Imaging ◽  
Field Imaging

Phase-Dield Simulation of Rhombohedral and Tetragonal Phases in Ferroelectric Single Crystals

Aerospace ◽  
2006 ◽  
Author(s):  
T. Liu ◽  
C. S. Lynch
Keyword(s):  
Free Energy ◽  
Phase Transformations ◽  
Single Crystals ◽  
Electric Fields ◽  
Tetragonal Phase ◽  
Ferroelectric Materials ◽  
Integration Scheme ◽  
Ferroelectric Crystal ◽  
Domain Structures ◽  
Tdgl Equation

Ferroelectric materials exhibit spontaneous polarization and domain structures below the Curie temperature. In this work the phase field approach has been used to simulate phase transformations and the formation of ferroelectric domain structures. The evolution of phases and domain structures was simulated in ferroelectric single crystals by solving the time dependent Ginzburg-Landau (TDGL) equation with polarization as the order parameter. In the TDGL equation the free energy of a ferroelectric crystal is written as a function of polarization and applied fields. Change of temperature as well as application of stress and electric fields leads to change of the free energy and evolution of phase states and domain structures. In this work the finite difference method was implemented for the spatial description of the polarization and the temporal evolution of polarization field was computed by solving the TDGL equation with an explicit time integration scheme. Cubic to tetragonal, cubic to rhombohedral and rhombohedral to tetragonal phase transformations were modeled, and the formation of domain structures was simulated. Field induced polarization switching and rhombohedral to tetragonal phase transition were simulated.

scholarly journals Measurement of the Near Field Distribution of a Microwave Horn Using a Resonant Atomic Probe

2019 ◽  
Vol 9 (22) ◽  
pp. 4895 ◽  
Author(s):  
Jingxu Bai ◽  
Jiabei Fan ◽  
Liping Hao ◽  
Nicholas L. R. Spong ◽  
Yuechun Jiao ◽  
...  
Keyword(s):  
Field Distribution ◽  
Electric Fields ◽  
Microwave Field ◽  
Electric Field Distribution ◽  
Near Field ◽  
Field Measurements ◽  
Amplitude Distribution ◽  
Field Coupling ◽  
All Optical ◽  
Atomic Probe

We measure the near field distribution of a microwave horn with a resonant atomic probe. The microwave field emitted by a standard microwave horn is investigated utilizing Rydberg electromagnetically inducted transparency (EIT), an all-optical Rydberg detection, in a room temperature caesium vapor cell. The ground 6 S 1 / 2 , excited 6 P 3 / 2 , and Rydberg 56 D 5 / 2 states constitute a three-level system, used as an atomic probe to detect microwave electric fields by analyzing microwave dressed Autler–Townes (AT) splitting. We present a measurement of the electric field distribution of the microwave horn operating at 3.99 GHz in the near field, coupling the transition 56 D 5 / 2 → 57 P 3 / 2 . The microwave dressed AT spectrum reveals information on both the strength and polarization of the field emitted from the microwave horn simultaneously. The measurements are compared with field measurements obtained using a dipole metal probe, and with simulations of the electromagnetic simulated software (EMSS). The atomic probe measurement is in better agreement with the simulations than the metal probe. The deviation from the simulation of measurements taken with the atomic probe is smaller than the metal probe, improving by 1.6 dB. The symmetry of the amplitude distribution of the measured field is studied by comparing the measurements taken on either side of the field maxima.

Nonlinear Forced Vibrations of Laminated Piezoelectric Plates

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Muhammad Tanveer ◽  
Anand V. Singh
Keyword(s):  
Electric Fields ◽  
Mechanical Load ◽  
Numerical Procedure ◽  
Laminated Composite ◽  
Composite Plates ◽  
Forced Vibrations ◽  
Homogeneous Material ◽  
Displacement Fields ◽  
Electrical Loads ◽  
Piezoelectric Plates

A numerical approach is presented for linear and geometrically nonlinear forced vibrations of laminated composite plates with piezoelectric materials. The displacement fields are defined generally by high degree polynomials and the convergence of the results is achieved by increasing the degrees of polynomials. The nonlinearity is retained with the in-plane strain components only and the transverse shear strains are kept linear. The electric potential is approximated layerwise along the thickness direction of the piezoelectric layers. In-plane electric fields at the top and bottom surfaces of each piezoelectric sublayer are defined by the same shape functions as those used for displacement fields. The equation of motion is obtained by the Hamilton’s principle and solved by the Newmark’s method along with the Newton–Raphson iterative technique. Numerical procedure presented herein is validated by successfully comparing the present results with the data published in the literature. Additional numerical examples are presented for forced vibration of piezoelectric sandwich simply supported plates with either a homogeneous material or laminated composite as core. Both linear and nonlinear responses are examined for mechanical load only, electrical load only, and the combined mechanical and electrical loads. Displacement time histories with uniformly distributed load on the plate surface, electric volts applied on the top and bottom surfaces of the piezoelectric plates, and mechanical and electrical loads applied together are presented in this paper. The nonlinearity due to large deformations is seen to produce stiffening effects, which reduces the amplitude of vibrations and increases the frequency. On the contrary, antisymmetric electric loading on the nonlinear response of piezoelectric sandwich plates shows increased amplitude of vibrations.

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