Electrodynamic Device Research Articles

Address Energy Delivery Technologies Based on The Hybrid Electrodynamic Processes

An effective tool has been identified for transferring technologies for processing food raw materials onto the rails of the nano-eco-industry — these are hybrid processes in electrodynamic devices. The aim of the work is a comprehensive study of hybrid processes in microwave electrodynamic systems. To achieve the goal, an experimental stand was created, which made it possible to visually confirm the effects of mechanical diffusion and establish the influence of key parameters on the kinetics and energy of hybrid processes. The working section — a model of a capillary-porous structure — was a bundle of calibrated glass tubes. When processing experimental data, the dependences of the influence of field power, channel diameter, temperature, and beam orientation on the kinetics and energy of the hybrid process were obtained. The most significant result of the work is the use of certain modes of organizing hybrid processes to control the extraction process in electrodynamic devices of three types: volumetric, film and circulation. Tests of these structures confirmed the formulated hypotheses of the formation of a hybrid process. The importance of the work lies in the fact that it is shown that the effect of mechanical diffusion is most powerfully manifested in electrodynamic extractors of the circulation type and energy consumption in electrodynamic extractors of the volumetric type is 1.4 times lower, film extractors are 1.5 times lower, and circulation type ones are 1.9 times lower, than in devices of traditional design.

Assessment of the tolerance angle for pedicle screw insertion.

Cannulation process intervenes before implantation of pedicle screw and depends on the surgeon's experience. A reliable experimental protocol has been developed for the characterization of the slipping behavior of the surgical tool on the cortical shell simulated by synthetic materials. Three types of synthetic foam samples with three different densities were tested using an MTS Acumen 3 A/T electrodynamic device with a tri-axis 3 kN Kistler load cell mounted on a surgical tool, moving at a constant rotational speed of 10° mm-1 and performing a three-step cannulation test. Cannulation angle varied between 10° and 30°. Synthetic samples were scanned after each tests, and cannulation coefficient associated to each perforation section was computed. Reproducibility tests resulted in an ICC for Sawbone samples of 0.979 (p < 0.001) and of 0.909 (p < 0.001) for Creaplast and Sawbone samples. Cannulation coefficient and maximum force in Z-axis are found the best descriptors of the perforation. Angular threshold for perforation prediction was found to be 17.5° with an area under the curve of the Receiver Operating Characteristic of 89.5%. This protocol characterizes the cannulation process before pedicle screw insertion and identifies the perforation tool angle until which the surgical tool slips on the cortical shell depending on bone quality.

Sliding on cortical shell: Biomechanical characterization of the vertebral cannulation for pedicle screw insertion

BackgroundPedicular screws pull-out has been well studied unlike their insertion. A need for characterizing cannulation before pedicle screw implantation is highlighted in literature and offers promising prospects for future intra-operation instrumentation. A reliable cannulation protocol for ex-vivo testing in swine and cadaver vertebrae is presented in this work to predict extra pedicular perforation. MethodsAn MTS Acumen 3 A/T electrodynamic device, with a tri-axis 3 kN Kistler load cell mounted on a surgical tool was used to reproduce surgeon's gesture by moving at a constant rotational speed of 10°/mm and performing a three-section test. Perforation of the pedicle's cortical shell was planned through a design of experiment on the surgical tool angle at the entry point. Samples were scanned before and after mechanical tests and reproducibility of the protocol was tested on synthetic foam. Computation of the angle between cannulation tool and pedicle cortical shell was performed as well as cannulation coefficient of each perforation section. FindingsA total of 68 pedicles were tested: 19 perforated and 21 non-perforated human pedicles, 17 perforated and 16 non-perforated swine pedicles. The reproducibility of the protocol for cannulation coefficient computation resulted in an intraclass correlation coefficient of 0.979. Cannulation coefficients results presented variability within spinal levels as well as between swine and human model. Correlation between bone density and cannulation coefficient was found significant (p < 0.005). Torque measurement was found to be the best predictor of perforation. Threshold of angle for prediction of perforation was found to be 21.7°. InterpretationCharacterizing pedicle cannulation enables to predict extra pedicular perforation. Influence of bone mineral density and patient-specific morphology on pedicle cannulation has been highlighted together with a comparison of swine and cadaver models.

The Design of a Remediation Device for Heavy Metal Contaminated Soil Under Digital Economy

Since entering the new era, the economy has grown rapidly and the economic strength has improved significantly, but it is accompanied by resource and environmental problems caused by the high pollution and high energy consumption growth model. Realizing the transformation of economic development from “incremental” to “increasing quality” and promoting economic green transformation has become one of the main development goals of China in the next stage. With the rapid development of China’s social economy, the changes of industrialization, urbanization and agricultural intensification are getting faster and faster. The discharge of industrial “three wastes” and urban domestic wastewater has gradually increased, and a large amount of chemical fertilizers and pesticides have been applied to rural arable land. It accelerates soil heavy metal pollution. Electrodynamic remediation technology, as an emerging soil in situ remediation technology, has attracted wide attention due to its advantages of wide range of pollutant removal, low cost and good effect. In this paper, a remediation device for heavy metal-contaminated soil is designed based on electrodynamic remediation technology. That is, on the basis of the digital economy, an electrolyte circulation mechanism with high adsorption of heavy metal ions is introduced. In this paper, the feasibility of electrokinetic remediation of the contaminated soil was investigated, and the effects of electrolyte type, voltage, and remediation time on the removal of heavy metals were studied. The following results were obtained through a series of experimental studies: the pH values of region A in E1, E2, and E3 were 3.24, 3.18, and 3.09, respectively. The current peak values of E1, E2 and E4 are 0.44, 0.68 and 0.75 mA respectively. E4 had the best adsorption effect on heavy metal cadmium ions, with an average adsorption rate of 7.3%. The results show that the electrodynamic remediation device can effectively remove heavy metals in soil. It can also recycle the electrolyte solution, which is an environmentally friendly repair device.

Macroscopic Circuit Quantum Electrodynamics: A New Look Toward Developing Full-Wave Numerical Models

Devices built using superconducting circuits are a popular approach being pursued to develop quantum information processing hardware. These systems involve the quantized interactions of electromagnetic fields with large coherent collections of charges in superconductors, and so are typically referred to as macroscopic circuit quantum electrodynamics (QED) devices or simply circuit QED devices. Although significant progress has been made recently, substantial engineering efforts are required to improve performance and scale these devices so they can address problems of practical interest. Performing these engineering efforts is difficult due to the absence of rigorous numerical modeling approaches. This work begins to address this by providing a new mathematical description of a commonly used circuit QED system, a transmon qubit coupled to microwave transmission lines. Expressed in terms of three-dimensional vector fields, our new model is better suited to developing rigorous numerical solvers than approximate lumped element circuit descriptions used in the literature. We present details on the quantization of our model, and derive equations of motion for the coupled field-transmon system. These results can be used in developing full-wave solvers in the future. To make this work more accessible, we assume a limited amount of training in quantum physics and provide many background details.

Control of the transition frequency of a superconducting flux qubit by longitudinal coupling to the photon number degree of freedom in a resonator

We control transition frequency of a superconducting flux qubit coupled to a frequency-tunable resonator comprising a direct current superconducting quantum interference device (dc-SQUID) by microwave driving. The dc-SQUID mediates the coupling between microwave photons in the resonator and a flux qubit. The polarity of the frequency shift depends on the sign of the flux bias for the qubit and can be both positive and negative. The absolute value of the frequency shift becomes larger by increasing the photon number in the resonator. These behaviors are reproduced by a model considering the magnetic interaction between the flux qubit and dc-SQUID. The tuning range of the transition frequency of the flux qubit reaches $\approx$ 1.9 GHz, which is much larger than the ac Stark/Lamb shift observed in the dispersive regime using typical circuit quantum electrodynamics devices.

Millimeter-Wave Gyrotron Research System. I. Description of the Facility

We describe a series of gyrotron facilities developed at the Institute of Applied Physics of the Russian Academy of Sciences for studying physical processes during interaction of millimeter-wave electromagnetic radiation and matter. This paper presents the universal principle of designing such systems on the basis of a facility having an output radiation power of 5 kW at a frequency of 24 GHz. The main components of the facility and their technical parameters are described. Design of high-efficiency radiation sources and radiation transmission lines for various research applications is a sophisticated radiophysical problem, and the need for long-term stable operation with automatic adjustment of the parameters of the generation regime requires unique engineering solutions. Application of multimode electrodynamic devices in the radiation transmission line allows one to treat materials with significantly different dielectric properties, in particular, heat them up to temperatures of about (and exceeding) 2000°C. The vacuum-tight working chamber of the facility is a high-Q untuned cavity resonator having a volume of about 0.1 m3, in which microwave heating of items with characteristic dimensions of more than 10 cm can be performed. The automatic control system of the facility ensures its reliable and long-term failure-free operation.

Tunable SNAP microresonators via internal ohmic heating

We demonstrate a thermally tunable surface nanoscale axial photonics (SNAP) platform. Stable tuning is achieved by heating a SNAP structure fabricated on the surface of a silica capillary with a metal wire positioned inside. Heating a SNAP microresonator with a uniform wire introduces uniform variation of its effective radius which results in constant shift of its resonance wavelengths. Heating with a nonuniform wire allows local nanoscale variation of the capillary effective radius, which enables differential tuning of the spectrum of SNAP structures, as well as the creation of temporary SNAP microresonators that exist only when current is applied. As an example, we fabricate two bottle microresonators coupled to each other and demonstrate differential tuning of their resonance wavelengths into and out of degeneracy with precision better than 0.2pm. The developed approach is beneficial for ultra-precise fabrication of tunable ultralow loss parity-time symmetric, optomechanical, and cavity quantum electrodynamics (QED) devices.

Metamaterial Perfect Absorber Analyzed by a Meta-cavity Model Consisting of Multilayer Metasurfaces

We demonstrate that the metamaterial perfect absorber behaves as a meta-cavity bounded between a resonant metasurface and a metallic thin-film reflector. The perfect absorption is achieved by the Fabry-Perot cavity resonance via multiple reflections between the “quasi-open” boundary of resonator and the “close” boundary of reflector. The characteristic features including angle independence, ultra-thin thickness and strong field localization can be well explained by this meta-cavity model. With this model, metamaterial perfect absorber can be redefined as a meta-cavity exhibiting high Q-factor, strong field enhancement and extremely high photonic density of states, thereby promising novel applications for high performance sensor, infrared photodetector and cavity quantum electrodynamics devices.

Foundations of Numerical Simulation and Design of Electrodynamic Devices for the Creation and Disintegration of Water-Oil Emulsions

Different methods for the numerical description of the behavior of a fluid–fluid interface in an electric field are proposed. A variation in the base system of equations for dielectrics and weakly conducting fluids is demonstrated. A deterministic approach to the description of two-phase flows traveling under the effect of an electric field is used. The system of equations proposed by G. A. Ostroumnov is adopted as a basis for a quantitative description of electrohydrodynamic phenomena. The proposed approach is used in numerical simulation of processes that occur in the intra-electrode space of electrodispersers and electrocoalescers in order to optimize their design and attain the maximal effect of separation with minimum energy costs.

An architecture for integrating planar and 3D cQED devices

Numerous loss mechanisms can limit coherence and scalability of planar and 3D-based circuit quantum electrodynamics (cQED) devices, particularly due to their packaging. The low loss and natural isolation of 3D enclosures make them good candidates for coherent scaling. We introduce a coaxial transmission line device architecture with coherence similar to traditional 3D cQED systems. Measurements demonstrate well-controlled external and on-chip couplings, a spectrum absent of cross-talk or spurious modes, and excellent resonator and qubit lifetimes. We integrate a resonator-qubit system in this architecture with a seamless 3D cavity, and separately pattern a qubit, readout resonator, Purcell filter, and high-Q stripline resonator on a single chip. Device coherence and its ease of integration make this a promising tool for complex experiments.

Ultrahigh quality factor in a metal-embedded semiconductor microdisk cavity.

We numerically and theoretically investigate electrodynamics of a metal-embedded semiconductor microdisk cavity. The electrodynamics of a cavity mode is discussed from the viewpoint of quantum mechanics, which clarifies the condition for high Q factor. Using numerical calculations, we optimize the cavity structure and show that the Q factor can be increased up to 1,700,000. Our study suggests that the metal-embedded cavity is a promising candidate for cavity quantum electrodynamics (QED) devices.

Electromagnetic simulation of frequency characteristics of the directional coupler beamforming system of phased antenna array

The influence of coaxial-stripline transitions in the frequency characteristics of the directional coupler, eg. Conclusions about the possibility of assessing the accuracy in modeling the electrodynamic symmetric devices.

Influence of Electrical Conductivity of Nonmagnetic Conductor in Electrodynamic Suspension Device using AC Electromagnets Driven by High Frequency Current

Influence of Electrical Conductivity of Nonmagnetic Conductor in Electrodynamic Suspension Device using AC Electromagnets Driven by High Frequency Current

Convergence condition for non-linear electrodynamic devices

For electrodynamic structures with non-linear properties of surface impedance conditions for existence of a single periodic mode in case of periodic external excitation (convergence condition) are obtained using non-linear integral equations method. Modeling results for a strip vibrator with various characteristics of surface impedance are presented. On this example we demonstrate that in non-convergent structures under certain conditions several modes may exist in case of the same parameters.

Chaos in a generalized Lorenz system

A three-component dynamic system describing a quantum cavity electrodynamic device with a pumping and nonlinear dissipation is studied. Various dynamical regimes are investigated in terms of divergent trajectories approaches and fractal statistics. It has been shown that stable and unstable dissipative structures type of limit cycles can be formed in such system, with variation of pumping and nonlinear dissipation rates. Transitions to chaotic regime and the corresponding chaotic attractor are studied in detail.

Investigations of a coherently driven semiconductor optical cavity QED system

Chip-based cavity quantum electrodynamics (QED) devices consisting of a self-assembled InAs quantum dot (QD) coupled to a high quality factor GaAs microdisk cavity are coherently probed through their optical channel using a fiber taper waveguide. We highlight one particularly important aspect of this all-fiber measurement setup, which is the accuracy to which the optical coupling level and optical losses are known relative to typical free-space excitation techniques. This allows for precise knowledge of the intracavity photon number and measurement of absolute transmitted and reflected signals. Resonant optical spectroscopy of the system under both weak and strong driving conditions are presented, which when compared with a quantum master equation model of the system allows for determination of the coherent coupling rate between QD exciton and optical cavity mode, the different levels of elastic and inelastic dephasing of the exciton state, and the position and orientation of the QD within the cavity. Pump-probe measurements are also performed in which a far off-resonant red-detuned control laser beam is introduced into the cavity. Rather than producing a measurable ac Stark shift in the exciton line of the QD, we find that this control beam induces a saturation of the resonant system response. The broad photoluminescence spectrum resulting from the presence of the control beam in the cavity points to sub-band-gap absorption in the semiconductor, and the resulting free-carrier generation, as the likely source of system saturation.

Registration of single quantum dots using cryogenic laser photolithography

We have registered the position of single InGaAs quantum dots using a cryogenic laser photolithography technique. This is an important advance towards the reproducible fabrication of solid-state cavity quantum electrodynamic devices, a key requirement for commercial exploitation of quantum information processing. The quantum dot positions were registered with an estimated accuracy of 50nm by fabricating metal alignment markers around them. Photoluminescence spectra from quantum dots before and after marker fabrication were identical except for a small redshift (∼1nm), probably introduced during the reactive ion etching.

Generation of photon number states on demand

Experiments with single atoms have become routine. In this paper two groups of these experiments will be reviewed with special emphasis on applications to study quantum phenomena in the atom-radiation interaction. The first one deals with the one-atom maser and the second one with another cavity quantum electrodynamic device on the basis of trapped ions. The latter device has interesting applications in quantum computing and quantum information.

Model order reduction and equivalent circuit extraction for fit discretized electromagnetic systems

AbstractIn this paper a new approach for model order reduction of electrodynamic devices discretized by the finite integration theory is presented. It has two main applications: The fast frequency sweep of the transfer behaviour of resonant filters and the extraction of general equivalent circuits simplifying coupled circuit–electromagnetic simulations. The proposed two‐step Lanczos (TSL) algorithm combines a Lanczos based projection in the first step to pre‐reduce the non‐inverted system with a PVL‐like algorithm in the second step to get an optimal Padé approximation. This algorithm drastically reduces the computational complexity of model order reduction while maintaining the same accuracy as direct PVL. By applying it to a curl–curl formulation of the system, the computational cost is further reduced by a factor of two. By use of a projection method the curl–curl formulation can also be extended to lossy systems. Additionally, the method keeps the system stable, passive, and real throughout the process—an important prerequisite for the interpretation of the model as an equivalent network. Copyright © 2002 John Wiley &amp; Sons, Ltd.