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8,600
On-a-chip biosensing based on all-dielectric nanoresonators
physics.app-ph
Nanophotonics has become a key enabling technology in biomedicine with great promises in early diagnosis and less invasive therapies. In this context, the unique capability of plasmonic noble metal nanoparticles to concentrate light on the nanometer scale has widely contributed to biosensing and enhanced spectroscopy. ...
physics
8,601
A THz Slot Antenna Optimization Using Analytical Techniques
physics.app-ph
Slot antennas are very popular microwave antennas and slotted wave guides are used for high frequency radar systems. A thin slot in an infinite ground plane is the complement to a dipole in free space. This was described by H.G. Booker [2] who extended Babinet's principle from optics to show that the slot will have the...
physics
8,602
Can Distribution Grids Significantly Contribute to Transmission Grids' Voltage Management?
physics.app-ph
Power generation in Germany is currently transitioning from a system based on large, central, thermal power plants to one that heavily relies on small, decentral, mostly renewable power generators. This development poses the question how transmission grids' reactive power demand for voltage management, covered by centr...
physics
8,603
Self-supporting structure design in additive manufacturing through explicit topology optimization
physics.app-ph
One of the challenging issues in additive manufacturing (AM) oriented topology optimization is how to design structures that are self-supportive in a manufacture process without introducing additional supporting materials. In the present contribution, it is intended to resolve this problem under an explicit topology op...
physics
8,604
Nuclear Data and Fuel/Assembly Manufacturing Uncertainties Analysis and Preliminary Validation of SUACL
physics.app-ph
As the sensitivity and uncertainty analysis of nuclear system can provide more confident bounds for the Best-estimate Prediction used to assess the performance and safety of nuclear plant, the uncertainty and sensitivity analysis has been a component of analysis of nuclear system. Both the cross section uncertainty and...
physics
8,605
Pinhole induced efficiency variation in perovskite solar cells
physics.app-ph
Process induced efficiency variation is a major concern for all thin film solar cells, including the emerging perovskite based solar cells. In this manuscript, we address the effect of pinholes or process induced surface coverage aspects on the efficiency of such solar cells through detailed numerical simulations. Inte...
physics
8,606
Giant electrostrain of 0.57% in a periodically orthogonal poled lead titanate zirconate ceramic via reversible domain switching
physics.app-ph
The widely used ferroelectric ceramics based actuators always suffer from small output strains (typically ~0.1-0.15%). Non-180{\deg} domain switching can generate large strain in ferroelectrics but it is usually irreversible. In this work, we tailored the domain structures in a soft lead titanate zirconate (PZT) cerami...
physics
8,607
Tunable, synchronized frequency down-conversion in magnetic lattices with defects
physics.app-ph
We study frequency conversion in nonlinear mechanical lattices, focusing on a chain of magnets as a model system. We show that by inserting mass defects at suitable locations, we can introduce localized vibrational modes that nonlinearly couple to extended lattice modes. The nonlinear interaction introduces an energy t...
physics
8,608
The Response of Conductive-Fiber Reinforced Composites to Electric Field
physics.app-ph
An analytical procedure, which couples electric, magnetic, thermal and mechanical effects is presented for the prediction of the response of unidirectional fiber-reinforced composites that are subjected to electric field, applied in the fibers' direction. It is assumed that at least one of the phases of the composite (...
physics
8,609
The Effects of Superheating Treatment on Distribution of Eutectic Silicon Particles in A357-Continuous Stainless Steel Composite
physics.app-ph
In the present study, superheating treatment has been applied on A357 reinforced with 0.5 wt. % (Composite 1) and 1.0 wt.% (Composite 2) continuous stainless steel composite. In Composite 1 the microstructure displayed poor bonding between matrix and reinforcement interface. Poor bonding associated with large voids als...
physics
8,610
Dynamic balancing of super-critical rotating structures using slow-speed data via parametric excitation
physics.app-ph
High-speed machinery is often designed to pass several $"$critical$"$ speeds, where vibration levels can be very high. To reduce vibrations, rotors usually undergo a mass balancing process, where the machine is rotated at its full speed range, during which the dynamic response near critical speeds can be measured. High...
physics
8,611
Vertical Bifacial Solar Farms: Physics, Design, and Global Optimization
physics.app-ph
There have been sustained interest in bifacial solar cell technology since 1980s, with prospects of 30-50% increase in the output power from a stand-alone single panel. Moreover, a vertical bifacial panel reduces dust accumulation and provides two output peaks during the day, with the second peak aligned to the peak el...
physics
8,612
Low-frequency wide band-gap elastic/acoustic meta-materials using the K-damping concept
physics.app-ph
The terms "acoustic/elastic meta-materials" describe a class of periodic structures with unit cells exhibiting local resonance. This localized resonant structure has been shown to result in negative effective stiffness and/or mass at frequency ranges close to these local resonances. As a result, these structures presen...
physics
8,613
Tunable Extremely Asymmetric Acoustic Metasurfaces Made by Coupled Membrane Resonators
physics.app-ph
We report the experimental demonstration of tunable asymmetric acoustic metasurfaces with extreme contrast, made by two decorated membrane resonators (DMRs) coupled via a sealed air column. The front side of the metasurface is impedance matched to air and perfectly absorbing, while the backside is hard and totally refl...
physics
8,614
Comment on 'Table-like magnetocaloric effect and enhanced refrigerant capacity in Eu8Ga16Ge30-EuO composite materials' [Appl. Phys. Lett. 99, 162513 (2011)]
physics.app-ph
This is a comment on 'Table-like magnetocaloric effect and enhanced refrigerant capacity in Eu8Ga16Ge30-EuO composite materials', published few years ago. Refrigerant Capacity (RC) and Relative Cooling Power (RCP) are properties that characterize the magnetocaloric effect. RCP and mainly RC are also important to charac...
physics
8,615
High speed optical processing via four-wave-mixing in a silicon waveguide
physics.app-ph
We demonstrate all-optical demultiplexing at 160 Gigabits per second in the C-band, based on nonlinear optics using four-wave mixing (FWM) in a silicon nanowire. We achieve error-free operation with a penalty of ~ 3.9dB.
physics
8,616
Simultaneous summation and recognition effects for a dual-emitter light-induced neuromorphic device
physics.app-ph
We propose and fabricate a dual-emitter light-induced neuromorphic device composed of two light-induced devices with a common collector and base. Two InGaN multiple quantum well diodes (MQW-diodes) are used as the emitters to generate light, and one InGaN MQW-diode is used as the common collector to absorb the emitted ...
physics
8,617
Spoof Surface Plasmon Polariton Leaky-Wave Antennas using Periodically Loaded Patches above PEC and AMC Ground Planes
physics.app-ph
This paper proposes two spoof surface plasmon polariton (SSPP) leaky-wave antennas using periodically loaded patches above perfect electric conductor (PEC) and artificial magnetic conductor (AMC) ground planes, respectively. The SSPP leaky-wave antenna is based on a SSPP transmission line, along which circular patches ...
physics
8,618
A study of size-dependent properties of MoS2 monolayer nanoflakes using density-functional theory
physics.app-ph
Novel physical phenomena emerge in ultra-small sized nanomaterials. We study the limiting small-size-dependent properties of MoS$_{2}$ monolayer rhombic nanoflakes using density-functional theory on structures of size up to Mo$_{35}$S$_{70}$ (1.74~nm). We investigate the structural and electronic properties as function...
physics
8,619
A Two-element Parasitic Antenna Approaching the Minimum Q-factor at a Given Directivity
physics.app-ph
In this paper we investigate a super-directive antenna based on a parasitic structure with a circumscribing sphere of diameter 69 mm corresponding to 0.2$\lambda$@880 MHz. The antenna is modeled, simulated, measured, and it is also evaluated against the new Q-factor bound for small antennas at a given total directivity...
physics
8,620
Titanium dioxide hole-blocking layer in ultra-thin-film crystalline silicon solar cells
physics.app-ph
One of the remaining obstacles to approaching the theoretical efficiency limit of crystalline silicon (c-Si) solar cells is the exceedingly high interface recombination loss for minority carriers at the Ohmic contacts. In ultra-thin-film c-Si solar cells, this contact recombination loss is far more severe than for trad...
physics
8,621
Extended social force model with a dynamic navigation field for bidirectional pedestrian flow
physics.app-ph
An extended social force model with a dynamic navigation field is proposed to study bidirectional pedestrian movement. The dynamic navigation field is introduced to describe the desired direction of pedestrian motion resulting from the decision-making processes of pedestrians. The macroscopic fundamental diagrams obtai...
physics
8,622
Nanodiamond arrays on glass for quantification and fluorescence characterisation
physics.app-ph
Quantifying the variation in emission properties of fluorescent nanodiamonds is important for developing their wide-ranging applicability. Directed self-assembly techniques show promise for positioning nanodiamonds precisely enabling such quantification. Here we show an approach for depositing nanodiamonds in pre-deter...
physics
8,623
Differential ghost imaging in time domain
physics.app-ph
Differential ghost imaging was attempted in time domain, i.e., temporal differential ghost imaging (TDGI), using pseudo-randomized light pulses and a temporal object consisting of no-return-to-zero bit patterns of varying duty. Evaluation of the signal-to-noise characteristics by taking account of errors due to false c...
physics
8,624
Resistive switching in MoSe$_{2}$/BaTiO$_{3}$ hybrid structures
physics.app-ph
Here we study the resistive switching (RS) effect that emerges when ferroelectric BaTiO$_{3}$ (BTO) and few-layers MoSe$_{2}$ are combined in one single structure. The C-V loops reveal the ferroelectric nature of both Al/Si/SiO$_{x}$/BTO/Au and Al/Si/SiO$_{x}$/MoSe$_{2}$/BTO/Au structures and the high quality of the Si...
physics
8,625
Resonance control of graphene drum resonator in nonlinear regime by standing wave of light
physics.app-ph
We demonstrate the control of resonance characteristics of a drum type graphene mechanical resonator in nonlinear oscillation regime by the photothermal effect, which is induced by a standing wave of light between a graphene and a substrate. Unlike the conventional Duffing type nonlinearity, the resonance characteristi...
physics
8,626
Implementation of the KDamper concept using disc springs
physics.app-ph
The KDamper is a novel passive vibration isolation and damping concept, based essentially on the optimal combination of appropriate stiffness elements, which include a negative stiffness el-ement. Among others, KDamper can provide comparative advantages in the very low fre-quency range. It should be mentioned, that the...
physics
8,627
A charging method for electric vehicle using multi battery series mode
physics.app-ph
A charging method for electric vehicle using multi battery series mode which consisted of the following steps was introduced: the battery series is firstly charged at a constant power with a charging current of I1. When the terminal voltage over the battery series has reached the 1st threshold voltage, the charging cur...
physics
8,628
Band Gap Formation and Tunability in Stretchable Serpentine Interconnects
physics.app-ph
Serpentine interconnects are highly stretchable and frequently used in flexible electronic systems. In this work, we show that the undulating geometry of the serpentine interconnects will generate phononic band gaps to manipulate elastic wave propagation. The interesting effect of `bands-sticking-together' is observed....
physics
8,629
Impact of Junction Depth and Abruptness on the Activation and the Leakage Current in Germanium n$^{+}$/p Junctions
physics.app-ph
The phosphorous activation in Ge n$^{+}$/p junctions is compared in terms of junction depth, by using laser spike annealing at 860{\deg}C for 400$\mu$s. The reverse junction leakage is found to strongly depend on the abruptness of dopant profiles. A shallow and abrupt junction is shown to have lower phosphorous activat...
physics
8,630
Variation of field enhancement factor near the emitter tip
physics.app-ph
The field enhancement factor at the emitter tip and its variation in a close neighbourhood determines the emitter current in a Fowler-Nordheim like formulation. For an axially symmetric emitter with a smooth tip, it is shown that the variation can be accounted by a $\cos{\tilde{\theta}}$ factor in appropriately defined...
physics
8,631
A Highly Efficient Polarization-Independent Metamaterial-Based RF Energy-Harvesting Rectenna for Low-Power Applications
physics.app-ph
A highly-efficient multi-resonant RF energy-harvesting rectenna based on a metamaterial perfect absorber featuring closely-spaced polarization-independent absorption modes is presented. Its effective area is larger than its physical area, and so efficiencies of 230% and 130% are measured at power densities of 10 uW/cm2...
physics
8,632
A Metamaterial-inspired Approach to RF Energy Harvesting
physics.app-ph
We demonstrate an RF energy harvesting rectenna design based on a metamaterial perfect absorber (MPA). With the embedded Schottky diodes, the rectenna converts captured RF waves to DC power. The Fabry-Perot (FP) cavity resonance of the MPA greatly improves the amount of energy captured. Furthermore, the FP resonance ex...
physics
8,633
Tunable Optical Bistability and Optical Switching by Nonlinear Metamaterials
physics.app-ph
We demonstrate a nonlinear metamaterial in microwave frequency regime with hysteresis effect and bistable states, which can be utilized as a remotely controllable micro second switching device. A varactor loaded split-ring resonator (SRR) design which exhibits power and frequency dependent broadband tunability of the r...
physics
8,634
Enhanced Second-harmonic Generation Using Nonlinear Metamaterials
physics.app-ph
We demonstrate a nonlinear metamaterial which enhance higher order harmonics in microwave frequency regime. Nonlinearity in the structure is introduced by adding a varactor diode in the common slit of the double split ring resonator (DSRR) design. By engineering the structure such that inner ring resonance frequency of...
physics
8,635
Simultaneous readout of two adjacent bit tracks with a spin-torque oscillator
physics.app-ph
We propose a novel setup for a spin-torque oscillator reader in magnetic hard disk drive technology. Two adjacent bit tracks are to be read simultaneously, leading to high data transfer rate and increased resilience to noise as the lateral size of the oscillator device is allowed to remain larger than the bit width. We...
physics
8,636
High-Intensity Discharge Lamp and Duffing Oscillator - Similarities and Differences
physics.app-ph
The processes inside the arc tube of high-intensity discharge lamps are investigated by finite element simulations. The behavior of the gas mixture inside the arc tube is governed by differential equations describing mass, energy and charge conservation as well as the Helmholtz equation for the acoustic pressure and th...
physics
8,637
Organic solar cell design as a function of radiative quantum efficiency
physics.app-ph
We study the radiative decay, or fluorescence, of excitons in organic solar cells as a function of its geometrical parameters. Contrary to their non-radiative counterpart, fluorescence losses strongly depend on the environment. By properly tuning the thicknesses of the buffer layers between the active regions of the ce...
physics
8,638
Optimizing coating performance for diffusion under cyclic moisture exposure
physics.app-ph
Fickian diffusion is often used to model moisture transport through barrier coatings, where the goal is to protect an underlying substrate from the onset of corrosion caused by buildup of water or other aggressive species. Such coatings are often exposed to cyclic moisture, either in laboratory testing or in service du...
physics
8,639
Dipole-field-assisted charge extraction in metal-perovskite-metal back-contact solar cells
physics.app-ph
Hybrid organic-inorganic halide perovskites are low-cost solution-processable solar cell materials with photovoltaic properties that rival those of crystalline silicon. The perovskite films are typically sandwiched between thin layers of hole and electron transport materials, which efficiently extract photogenerated ch...
physics
8,640
On-Site Wireless Power Generation
physics.app-ph
Conventional wireless power transfer systems consist of a microwave power generator and a microwave power receiver separated by some distance. To realize efficient power transfer, the system is typically brought to resonance, and the coupled-antenna mode is optimized to reduce radiation into the surrounding space. In t...
physics
8,641
Atomic-scale Structural and Chemical Characterization of Hexagonal Boron Nitride Layers Synthesized at the Wafer-Scale with Monolayer Thickness Control
physics.app-ph
Hexagonal boron nitride (h-BN) is a promising two-dimensional insulator with a large band gap and low density of charged impurities that is isostructural and isoelectronic with graphene. Here we report the chemical and atomic-scale structure of CVD-grown wafer-scale (~25 cm2) h-BN sheets ranging in thickness from 1-20 ...
physics
8,642
Compact bilateral single conductor surface wave transmission line
physics.app-ph
A compact bilateral single conductor surface wave transmission line (TL) is proposed, converting the quasi-transverse electromagnetic (QTEM) mode of low characteristic impedance slotline into the transverse magnetic (TM) mode of single-conductor TL. The propagation constant of the proposed TL is decided by geometric pa...
physics
8,643
InGaN Metal-IN Solar Cell: optimized efficiency and fabrication tolerance
physics.app-ph
Choosing the Indium Gallium Nitride (InGaN) ternary alloy for thin films solar cells might yield high benefits concerning efficiency and reliability, because its bandgap can be tuned through the Indium composition and radiations have little destructive effect on it. It may also reveal challenges because good quality p-...
physics
8,644
Mini Review on the Significance Nano-Lubricants in Boundary Lubrication Regime
physics.app-ph
This article briefly reviews the significance nano-lubricants and assesses their effectiveness to provide the most promising approaches to reduce the friction and anti-wear/scuffing over the boundary regime. The main purpose of this review is to summarize the present knowledge about major advantages of the nanomaterial...
physics
8,645
Numerical analysis of flexible ultra-thin conformal antenna array
physics.app-ph
We present a flexible ultra-thin conformal patch antenna array operating in the Industrial, Scientific, and Medical (ISM) band (2.4-2.4835 GHz) for wireless sensor nodes. The antenna was designed on a flexible polyimide film (Kapton HN) substrate with the size of 95180.1 mm3 and the number of 7 radiating elements. The ...
physics
8,646
Large-aperture computational single-sensor microwave imager using 1-bit programmable coding metasurface at single frequency
physics.app-ph
The microwave imaging based on inverse scattering strategy holds important promising in the science, engineering, and military applications. Here we present a compressed-sensing (CS) inspired large- aperture computational single-sensor imager using 1-bit programmable coding metasurface for efficient microwave imaging, ...
physics
8,647
Factors Determining the Carrier Distribution in InGaN/GaN Multiple-Quantum-Well Light-Emitting Diodes
physics.app-ph
Factors determining the carrier distribution in InGaN/GaN multiple-quantum-well (MQW) light-emitting diodes (LEDs) are studied via photoluminescence and temperature-dependent electroluminescence spectra. Employing a dichromatic LED device, we demonstrate that the carrier recombination rate should be considered playing ...
physics
8,648
Experimental demonstration of an ultra-compact on-chip polarization controlling structure
physics.app-ph
We demonstrated a novel on-chip polarization controlling structure, fabricated by standard 0.18-um foundry technology. It achieved polarization rotation with a size of 0.726 um * 5.27 um and can be easily extended into dynamic polarization controllers.
physics
8,649
Enhancement of superconductivity in NbN nanowires by negative electron-beam lithography with positive resist
physics.app-ph
We performed comparative experimental investigation of superconducting NbN nanowires which were prepared by means of positive-and negative electron-beam lithography with the same positive tone Poly-methyl-methacrylate (PMMA) resist. We show that nanowires with a thickness 4.9 nm and widths less than 100 nm demonstrate ...
physics
8,650
Erasing and Correction of Liquid Metal Printed Electronics Made of Gallium Alloy Ink from the Substrate
physics.app-ph
Gallium-based liquid metals have recently been found important in a variety of newly emerging applications such as room temperature metal 3D printing, direct writing of electronics and biomedicine etc. In all these practices, one frequently encounters the situations that a printed circuit or track needs to be corrected...
physics
8,651
The Vapor-Solid-Solid Growth of Ge Nanowires on Ge (110) by Molecular Beam Epitaxy
physics.app-ph
We demonstrate Au-assisted vapor-solid-solid (VSS) growth of Ge nanowires (NWs) by molecular beam epitaxy (MBE) at 220 {\deg}C, which is compatible with the temperature window for Si-based integrated circuit. Low temperature grown Ge NWs hold a smaller size, similar uniformity and better fit with Au tips in diameter, i...
physics
8,652
A hybrid solution for simultaneous transfer of ultrastable optical frequency, RF frequency and UTC time-tags over optical fiber
physics.app-ph
We describe a fiber-optic solution for simultaneous distribution of all signals generated at todays most advanced time and frequency laboratories, i.e. an ultrastable optical reference frequency derived from an optical atomic clock, a radio frequency precisely linked to a realization of the SI-Second, and a realization...
physics
8,653
Time-Series Analysis of Photovoltaic Distributed Generation Impacts on a Local Distributed Network
physics.app-ph
Increasing penetration level of photovoltaic (PV) distributed generation (DG) into distribution networks will have many impacts on nominal circuit operating conditions including voltage quality and reverse power flow issues. In U.S. most studies on PVDG impacts on distribution networks are performed for west coast and ...
physics
8,654
Perfect Anomalous Reflection with an Aggressively Discretized Huygens' Metasurface
physics.app-ph
This paper investigates the discretization of a periodic metasurface and demonstrates how such a surface can achieve perfect anomalous reflection. Whilst most contemporary theoretical works on metasurfaces deal with continuous current or impedance distributions, we examine how discretization affects a metasurface, and ...
physics
8,655
Optimized Solar Photovoltaic Generation in a Real Local Distribution Network
physics.app-ph
Remarkable penetration of renewable energy in electric networks, despite its valuable opportunities, such as power loss reduction and loadability improvements, has raised concerns for system operators. Such huge penetration can lead to a violation of the grid requirements, such as voltage and current limits and reverse...
physics
8,656
Investigation and modeling of photocurrent collection process in multiple quantum well solar cells
physics.app-ph
Solar cells employing quantum wells can enhance the light absorption but suffer from the difficulty in photogenerated carrier extraction. Here, we analyzed the spectral response and the photocarrier collection mechanism of p-i-n multiple quantum well (MQW) solar cells using the effective-mobility model. Both the simula...
physics
8,657
Studies on thermal degradation behavior of nano silica loaded cotton and polyester fabrics
physics.app-ph
In this work cotton and polyester fabric were coated with silica nano particles using pad-dry-cure method. The prepared composite fabrics were analyzed in terms of change in their thermal degradation properties. The oxidative degradation characteristic of control and treated samples were studied using Thermo Gravimetri...
physics
8,658
Ultra-high and Tunable Sensitivity Leaky-Wave Scanning Using Gain-Loss C-section Phasers
physics.app-ph
A periodic leaky-wave antenna (LWA) with tuning capability and enhanced scanning sensitivity is introduced in this paper. This antenna leverages the concept of active Gain-Loss C-section pairs to tune the group delay of each antenna unit cell without affecting its magnitude response. This in turn changes the scanning a...
physics
8,659
Acoustic frequency filter based on anisotropic topological phononic crystals
physics.app-ph
There are growing efforts in constructing topological edge states in classical wave system. However, most of the work study the existence, creation and properties of the edge states, and the demonstration of application is highly desirable. Here, we present our design of a two-dimensional anisotropic phononic crystal t...
physics
8,660
Scanning Microwave Microscopy of Aluminum CMOS Interconnect Lines Buried in Oxide and Water
physics.app-ph
Using a scanning microwave microscope, we imaged in water aluminum interconnect lines buried in aluminum and silicon oxides fabricated through a state-of-the-art 0.13 um SiGe BiCMOS process. The results were compared with that obtained by using atomic force microscopy both in air and water. It was found the images in w...
physics
8,661
Low-Profile Spoof Surface Plasmon Polaritons Traveling-Wave Antenna for Endfire Radiation
physics.app-ph
This paper proposes a low-profile and highly efficient endfire radiating travelling-wave antenna based on spoof surface plasmon polaritons (SSPPs) transmission line. The aperture is approximately $0.32\lambda_0\times0.01\lambda_0$ where $\lambda_0$ is the space wavelength at the operational frequency 8 GHz. This antenn...
physics
8,662
Amplitude Stochastic Response of Rayleigh Beams to Randomly Moving Loads
physics.app-ph
We consider the problem of the nonlinear response of a Rayleigh beam to the passage of a train of forces moving with stochastic velocity. The Fourier transform and the theory of residues is used to estimate the mean-square amplitude of the beam, while the stochastic averaging method gives the stationary probability den...
physics
8,663
The pH-dependent electrical potential and elastic modulus of a nanoscale DNA film and the resultant bending signal for a microcantilever biosensor
physics.app-ph
This paper devotes to formulating several multiscale models to study the effect of pH-dependent ionic inhomogeneity on the electrical potential distributions and the graded elastic properties of a nanoscale DNA film and the related bending deflections of a microcantilever biosensor. First, the Langmuir isotherm was use...
physics
8,664
Ultrafast imprinting of topologically protected magnetic textures via pulsed electrons
physics.app-ph
Short electron pulses are demonstrated to trigger and control magnetic excitations, even at low electron current densities. We show that the tangential magnetic field surrounding a picosecond electron pulse can imprint topologically protected magnetic textures such as skyrmions in a sample with a residual Dzyaloshins...
physics
8,665
Inverse designed broadband all-dielectric electromagnetic metadevices
physics.app-ph
We present an all-dielectric metadevice platform realized by combining an inverse electromagnetic design computational method with additive manufacturing. As opposed to conventional flat metasurface based devices that are composed of resonant building blocks resulting in narrow band operation, our design approach creat...
physics
8,666
Helical and skyrmion lattice phases in three-dimensional chiral magnets: Effect of anisotropic interactions
physics.app-ph
In this work, we study the magnetic orders of the classical spin model with the anisotropic exchange and Dzyaloshinskii-Moriya interactions in order to understand the uniaxial stress effect in chiral magnets such as MnSi. Variational zero temperature (T) calculated results demonstrate that various helical orders can be...
physics
8,667
Grid-Connected Photovoltaic System for Active and Reactive Power Management
physics.app-ph
In this paper, the behavior of a photovoltaic (PV) system, with maximum power point tracking (MPPT) connected to three-phased grid has been investigated. A voltage source inverter (VSI) has been used to connect the photovoltaic system to the grid. The control strategy applied to control inverter switches is based on vo...
physics
8,668
Wave steering effects in anisotropic composite structures: Direct calculation of the energy skew angle through a finite element scheme
physics.app-ph
A systematic expression quantifying the wave energy skewing phenomenon as a function of the mechanical characteristics of a non-isotropic structure is derived in this study. A structure of arbitrary anisotropy, layering and geometric complexity is modelled through Finite Elements (FEs) coupled to a periodic structure w...
physics
8,669
Studying Cascading Overload Failures under High Penetration of Wind Generation
physics.app-ph
While power systems are reliable infrastructures, their complex interconnectivities allow for propagation of disturbances through cascading failures which causes blackouts. Meanwhile the ever increasing penetration level of renewable generation into power grids introduces a massive amount of uncertainty to the grid tha...
physics
8,670
A Silicon Photonic Integrated Frequency-Tunable Microwave Photonic Bandpass Filter
physics.app-ph
We report a fully integrated microwave photonic passband filter on a silicon photonic chip. The on-chip integrated microwave photonic filter (IMPF) consists of a high-speed phase modulator (PM), a thermally tunable high-Q micro-disk resonator (MDR), and a high-speed photodetector (PD). The bandpass filtering function o...
physics
8,671
Inverse Design of Conjugated Polymers from Computed Electronic Structure Properties: Model Chemistries of Polythiophenes
physics.app-ph
Using a diverse set of 100 oligothiophenes, extrapolated oligomer and polymer HOMO, LUMO and HOMO-LUMO gaps are shown to be accurately estimated from the computed values of the trimer HOMO, trimer LUMO and trimer HOMO-LUMO gaps. These simple approximations can be improved further through easy to calculate properties of...
physics
8,672
Acoustic emission source localization in thin metallic plates: a single-sensor approach based on multimodal edge reflections
physics.app-ph
This paper presents a new acoustic emission (AE) source localization for isotropic plates with reflecting boundaries. This approach that has no blind spot leverages multimodal edge reflections to identify AE sources with only a single sensor. The implementation of the proposed approach involves three main steps. First,...
physics
8,673
Spatial filtering of audible sound with acoustic landscapes
physics.app-ph
Acoustic metasurfaces manipulate waves with specially designed structures and achieve properties that natural materials cannot offer. Similar surfaces work in audio frequency range as well and lead to marvelous acoustic phenomena that can be perceived by human ears. Being intrigued by the famous Maoshan Bugle phenomeno...
physics
8,674
Tuning of bound states in the continuum by waveguide rotation
physics.app-ph
We consider acoustic wave transmission in non axisymmetric waveguide which consists of cylindrical resonator and two semi-infinite cylindrical waveguides whose axes are shifted relative to the resonator axis and each other by azimuthal angle $\Delta\phi$. We show that for rotation of one of attached waveguides the coup...
physics
8,675
Valley Vortex States in Sonic Crystals
physics.app-ph
Valleytronics is quickly emerging as an exciting field in fundamental and applied research. In this Letter, we study the acoustic version of valley states in sonic crystals and reveal a vortex nature of such states. Besides the selection rules established for exciting valley polarized states, a mimicked spin Hall effec...
physics
8,676
Strong 4-mode coupling of nanomechanical string resonators
physics.app-ph
We investigate mechanical mode coupling between the four fundamental flexural modes of two doubly-clamped, high-Q silicon-nitride nanomechanical string resonators. Strong mechanical coupling between the strings is induced by the strain mediated via a shared clamping point, engineered to increase the exchange of oscilla...
physics
8,677
Hydrogen loss and its improved retention in hydrogen plasma treated a-SiNx:H films: ERDA study with 100 MeV Ag7+ ions
physics.app-ph
Hydrogen loss from a-SiNx:H films under irradiation with 100 MeV Ag7+ ions using elastic recoil detection analysis (ERDA) experiments is reported. The results are explained under the basic assumptions of the molecular recombination model. The ERDA hydrogen counts are composed of two distinct hydrogen desorption process...
physics
8,678
Twist Coupled Kirigami Cellular Metamaterials and Mechanisms
physics.app-ph
Manipulation of thin sheets by folding and cutting offers opportunity to engineer structures with novel mechanical properties, and to prescribe complex force-displacement relationships via material elasticity in combination with the trajectory imposed by the fold topology. We study the mechanics of cellular Kirigami th...
physics
8,679
In-operando quantitation of Li concentration for commercial Li-ion rechargeable battery using high-energy X-ray Compton scattering
physics.app-ph
Compton scattering is one of the promising probe to quantitate of the Li under in-operando condition, since high-energy X-rays which have high penetration power into the materials are used as incident beam and Compton scattered energy spectrum have specific line-shape by the elements. We develop in-operando quantitatio...
physics
8,680
Thermodynamic limit of solar to fuel conversion for generalized photovoltaic-electrochemical system
physics.app-ph
Variability of the energy output throughout the day/night poses a major hurdle to the widespread adoption of photovoltaic systems. An integrated photovoltaic (PV) and electrochemical (EC)-storage system offers a solution, but the thermodynamic efficiency ({\eta}_sys) of the integrated system and the optimum configurati...
physics
8,681
UVC LEDs on Bulk AlN Substrates Using Silicon Nanomembranes for Efficient Hole Injection
physics.app-ph
As UV LEDs are explored at shorter wavelengths (< 280 nm) into the UVC spectral range, the crystalline quality of epitaxial AlGaN films with high Al compositions and inefficient hole injection from p-type AlGaN severely limit the LED performance and development. In this work, we report on 237 nm light emission with a r...
physics
8,682
Frequency shift keying by current modulation in a MTJ-based STNO with high data rate
physics.app-ph
Spin torque nano-oscillators are nanoscopic microwave frequency generators which excel due to their large frequency tuning range and agility for amplitude and frequency modulation. Due to their compactness, they are regarded as suitable candidates for applications in wireless communications, where cost-effective and CM...
physics
8,683
3D printable multimaterial cellular auxetics with tunable stiffness
physics.app-ph
Auxetic materials are a novel class of mechanical metamaterials which exhibit an interesting property of negative Poisson ratio by virtue of their architecture rather than composition. It has been well established that a wide range of negative Poisson ratio can be obtained by varying the geometry and architecture of th...
physics
8,684
Toward Microphononic Circuits on Chip: An Evaluation of Components based on High-Contrast Evanescent Confinement of Acoustic Waves
physics.app-ph
We investigate the prospects for micron-scale acoustic wave components and circuits on chip in solid planar structures that do not require suspension. We leverage evanescent guiding of acoustic waves by high slowness contrast materials readily available in silicon complementary metal-oxide semiconductor (CMOS) processe...
physics
8,685
Elastic Wave Eigenmode Solver for Acoustic Waveguides
physics.app-ph
A numerical solver for the elastic wave eigenmodes in acoustic waveguides of inhomogeneous cross-section is presented. Operating under the assumptions of linear, isotropic materials, it utilizes a finite-difference method on a staggered grid to solve for the acoustic eigenmodes of the vector-field elastic wave equation...
physics
8,686
Velocity-map imaging for emittance characterization of multiphoton-emitted electrons from a gold surface
physics.app-ph
A velocity-map-imaging spectrometer is demonstrated to characterize the normalized transverse emittance of photoemitted electron bunches. The two-dimensional (2D) projected velocity distribution images of photoemitted electrons are recorded by the detection system and analyzed to obtain the normalized transverse emitta...
physics
8,687
Mechanical Rainbow Trapping and Bloch Oscillations in Structured Elastic Beams
physics.app-ph
We demonstrate, both experimentally and numerically, the mechanical rainbow trapping effect and the mechanical Bloch oscillations for torsional waves propagating in chirped mechanical beams. After extensive simulations, three quasi-one-dimensional chirped structures were designed, constructed and experimentally charact...
physics
8,688
Effect of plasma formation on the double pulse laser excitation of cubic silicon carbide
physics.app-ph
We calculate the electron excitation in cubic silicon carbide (3C-SiC) caused by the intense femtosecond laser double pulses using time-dependent density functional theory (TDDFT). We assume the electron distributions in the valence band (VB) and the conduction band (CB) based on three different approaches to determine...
physics
8,689
Subwavelength sound screening by coupling space-coiled Fabry-Perot resonators
physics.app-ph
We explore broadband and omnidirectional low frequency sound screening based on locally resonant acoustic metamaterials. We show that the coupling of different resonant modes supported by Fabry-Perot cavities can efficiently generate asymmetric lineshapes in the transmission spectrum, leading to a broadband sound opaci...
physics
8,690
THz-Frequency Spin-Hall Auto-Oscillator Based on a Canted Antiferromagnet
physics.app-ph
We propose a design of a THz-frequency signal generator based on a layered structure consisting of a current-driven platinum (Pt) layer and a layer of an antiferromagnet (AFM) with easy-plane anisotropy, where the magnetization vectors of the AFM sublattices are canted inside the easy plane by the Dzyaloshinskii-Moriya...
physics
8,691
Effect of compressibility and aspect ratio on performance of long elastic seals
physics.app-ph
Recent experiments show no statistical impact of seal length on the performance of long elastomeric seals in relatively smooth test fixtures. Motivated by these results, we analytically and computationally investigate the combined effects of seal length and compressibility on the maximum differential pressure a seal ca...
physics
8,692
Alias-Free Basis for Modal Sensorless Adaptive Optics Using the Second Moment of Intensity
physics.app-ph
In theory of optical aberrations, an aberrated wavefront is represented by its coefficients in some orthogonal basis, for instance by Zernike polynomials. However, many wavefront measurement techniques implicitly approximate the gradient of the wavefront by the gradients of the basis functions. For a finite number of a...
physics
8,693
Development of Single-Shot Multi-Frame Imaging of Cylindrical Shock Waves in a Multi-Layered Assembly
physics.app-ph
We demonstrate single-shot multi-frame imaging of quasi-2D cylindrically converging shock waves as they propagate through a multi-layer target sample assembly. We visualize the shock with sequences of up to 16 images, using a Fabry-Perot cavity to generate a pulse train that can be used in various imaging configuration...
physics
8,694
Heterogeneous Memristive Devices Enabled by Magnetic Tunnel Junction Nanopillars Surrounded by Resistive Silicon Switches
physics.app-ph
Emerging non-volatile memories (NVMs) have currently attracted great interest for their potential applications in advanced low-power information storage and processing technologies. Conventional NVMs, such as magnetic random access memory (MRAM) and resistive random access memory (RRAM) suffer from limitations of low t...
physics
8,695
Strongly exchange-coupled and surface-state-modulated magnetization dynamics in Bi2Se3/YIG heterostructures
physics.app-ph
We report strong interfacial exchange coupling in Bi2Se3/yttrium iron garnet (YIG) bilayers manifested as large in-plane interfacial magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance (FMR). The IMA and spin mixing conductance reached a maximum when Bi2Se3 was around 6 quintuple-laye...
physics
8,696
Review on Modeling of Mechanical and Thermal Properties of Nano- and Micro-Composites
physics.app-ph
This article deals with the prediction of thermomechanical properties of fiber reinforced composites using several micromechanics models. These include strength of material approach, Halpin-Tsai equations, multi-phase mechanics of materials approaches, multi-phase Mori-Tanaka models, composite cylindrical assemblage mo...
physics
8,697
Dynamic Sensitivity Study of MEMS Capacitive Acceleration Transducer Based on Analytical Squeeze Film Damping and Mechanical Thermoelasticity Approaches
physics.app-ph
The dynamic behavior of a capacitive micro-electro-mechanical (MEMS) accelerometer is evaluated by using a theoretical approach which makes use of a squeeze film damping (SFD) model and ideal gas approach. The study investigates the performance of the device as a function of the temperature, from 228 K to 398 K, and pr...
physics
8,698
Synthesis of Negative Group Delay Using Lossy Coupling Matrix
physics.app-ph
In this paper, a systematic synthesis approach is proposed for achieving negative group delay responses using lossy coupling matrix. It is mathematically proved that, for a passive and reciprocal network, loss is the necessary condition to realize a negative group delay. Also, the optimum strategy is to place zeros and...
physics
8,699
Enormous sample scale-up from nanoliter to microliter in high field liquid state dynamic nuclear polarization
physics.app-ph
Dynamic nuclear polarization (DNP) enhances nuclear magnetic resonance (NMR) signals by transferring electron spin polarization to nuclei. As DNP requires microwave magnetic fields B1 strong enough to saturate electron spins, microwave resonators are generally used to achieve a sufficient B1, at the expense of restrict...
physics