Weak Electric Field Research Articles

Variation in properties of double-walled zigzag and armchair silicon nanotubes depending on SW defects and applied electric fields by SCC-DFTB method

The geometric structure and electrical properties of the zigzag DWSiNT (8,0)@(12,0) and armchair DWSiNT (5,5)@(7,7) perfect tubes with the same diameter are simulated by self-consistent charge density functional tight binding method (SCC-DFTB). We considered the defective tubes by introducing three types of Stone-Wales (SW) defects, and further investigated the impact of both strong and weak electric fields on these defective tubes. Calculations demonstrate that the atomic arrangement regularity, degree of buckling, stability, energy gap, and charge distribution strongly depend on the type of perfect tubes. Following the introduction of the SW defects, the symmetry of the tubes disappeared, and there is a obvious atomic aggregation occurring at the defects. The armchair tubes demonstrate a higher stability compared to zigzag tubes and all exhibit metallic properties. SWⅡ and SWⅢ defects in zigzag tubes result in a transition from semiconductor to semi-metallic properties. The number of charge transfer increases, and the degree of atomic aggregation is more dispersed. The effect of applied electric field strength on perfect zigzag tubes is more obvious. The weak field has minimally impacted on the stability, and the strong field makes the stability improved to some extent. The presence of a strong field caused the energy gap values of (8,0)@(12,0) tube decrease sharply, and all tubes are transformed into semi-metal or metal. The weak electric field has a more pronounced regulation of band gap within the range of 0 V/nm - 0.3 V/nm on the inner tube. The consequences of this investigation can certainly be helpful in future experimental studies.

Transient vortex dynamics and evolution of Bose metal from a 2D superconductor on MoS2

The true character of physical phenomena is thought to be reinforced as the system becomes disorder-free. In contrast, the two-dimensional (2D) superconductor is predicted to turn fragile and resistive away from the limit I → 0, B → 0, in the pinning-free regime. It is intriguing to note that the very vortices responsible for achieving superconductivity by pairing, condensation, and, thereby reducing the classical dissipation, render the state resistive driven by quantum fluctuations in the T → 0. While cleaner systems are being explored for technological improvements, the 2D superconductor turning resistive when influenced by weak electric and magnetic fields has profound consequences for quantum technologies. A metallic ground state in 2D is beyond the consensus of both Bosonic and Fermionic systems, and its origin and nature warrant a comprehensive theoretical understanding supplemented by in-depth experiments. A real-time observation of the influence of vortex dynamics on transport properties so far has been elusive. We explore the nature and fate of a low-viscous, clean, 2D superconducting state formed on an ionic-liquid gated few-layered MoS2 sample. The vortex-core being dissipative, the elastic depinning, intervortex interaction, and the subsequent dynamics of the vortex-lattice leave transient signatures in the transport characteristics. The temperature and magnetic field dependence of the transient nature and the noise characteristics of the magnetoresistance confirm that quantum fluctuations are solely responsible for the Bose metal state and the fragility of the superconducting state.

Review of: "Nanowires ( SiNWs) have high mobility and surface-to-volume ratio, which makes them easy to control using a weak electric field."

Review of: "Nanowires ( SiNWs) have high mobility and surface-to-volume ratio, which makes them easy to control using a weak electric field."

Mg content regulating built-in electric field for self-powered ZnO/MgxZn1-xO Schottky UV photodetector

In recent years, self-powered Schottky ultraviolet (UV) photodetectors (PDs) have attracted great attention due to their low manufacturing cost and zero-bias response. However, the development of high-performance self-powered Schottky devices is limited by the weak light response due to the internal weak electric field. Here, we introduce a MgxZn1-xO capping layer on ZnO and fabricate a ZnO/MgxZn1-xO heterojunction Schottky UV PD by using the sol-gel method. The improved device exhibits excellent self-powered characteristics and stability, specifically, an increase of 909% in photocurrent, an improvement of more than one order of magnitude in responsivity, and an improved linear dynamic region (LDR: 33.7 dB). The introduction of the MgxZn1-xO capping layer is responsible for the improved device performance, resulting in enhanced built-in electric field and depletion region width due to the increase of the Schottky barrier, thereby facilitating the separation and transport of photogenerated carriers. This work provides an effective way to fabricate high-performance self-powered ZnO Schottky UV PDs.

Passive electroreception in bottlenose dolphins (Tursiops truncatus): implication for micro- and large-scale orientation.

For the two dolphin species Sotalia guianensis (Guiana dolphin) and Tursiops truncatus (bottlenose dolphin), previous research has shown that the vibrissal crypts located on the rostrum represent highly innervated, ampullary electroreceptors and that both species are correspondingly sensitive to weak electric fields. In the present study, for a comparative assessment of the sensitivity of the bottlenose dolphin's electroreceptive system, we determined detection thresholds for DC and AC electric fields with two bottlenose dolphins. In a psychophysical experiment, the animals were trained to respond to electric field stimuli using the go/no-go paradigm. We show that the two bottlenose dolphins are able to detect DC electric fields as low as 2.4 and 5.5 µVcm-1, respectively, a detection threshold in the same order of magnitude as those in the platypus and the Guiana dolphin. Detection thresholds for AC fields (1, 5 and 25 Hz) were generally higher than those for DC fields, and the sensitivity for AC fields decreased with increasing frequency. Although the electroreceptive sensitivity of dolphins is lower than that of elasmobranchs, it is suggested that it allows for both micro- and macro-scale orientation. In dolphins pursuing benthic foraging strategies, electroreception may facilitate short-range prey detection and target-oriented snapping of their prey. Furthermore, the ability to detect weak electric fields may enable dolphins to perceive the Earth's magnetic field through induction-based magnetoreception, thus allowing large-scale orientation.

Synergistic effects of periodic weak spark and spatial electric field for one-step dispersion of carbon-based micro/nanomaterial agglomerates

Agglomeration and entanglement pose significant challenges in carbon-based micro/nanomaterials application, hindering the complete expression and fine-tuning of individual properties. A universal spatiotemporal electrified (STE) approach is proposed, which enables the efficient separation of individual constituents from agglomerates, achieving one-step dispersion in the gas phase. This process operates through two features: (1) periodic weak spark loosening and (2) spatial electric field attraction. The periodic weak spark, self-induced and automatically triggered by the material, generates induced electromagnetic fields and shock waves that facilitate repulsion, propulsion, and loosening of the agglomerate structure, endowing the material with capability to overcome the high frictional barriers. Simultaneously, the constructed spatial electric field continuously attracts, selectively separating and outputting individual micro/nanomaterials in real-time. This results in a one-step, concise dispersion process with additional benefits like alignment and blending. Overall, the STE approach has broad applicability and potential to unlock the full capabilities of micro/nanomaterials in various applications.

Correlated random walk and noise suppression in detecting electric fields

Detecting a weak electric field in a strong noisy background is always an interesting but hard task. We investigate the collective effects of charged Brownian particles in the presence of a weak electric field together with a strong noisy background field by numerical simulation. We show that the pattern formed by snapshots touched by the Brownian particles on one boundary surface can manifest the direction of an applied weak electric field but will be spoiled if there exists a strong noisy background. Moreover, we find that the influence of noise can be suppressed effectively if the correlations caused by the inter-particle electric interaction are taken into account. This work is expected to provide a new angle of view: correlated random walk plays a constructive role in noise suppression.

A ReaxFF and DFT study of effect and mechanism of an electric field on JP-10 fuel pyrolysis

To investigate the sustainable use of electric fields in improving aviation fuel combustion efficiency, a ReaxFF molecular dynamics simulation was conducted using exo-TCD (exo-tetrahydrocyclopentadiene) as the major component of JP-10 fuel. The study aimed to investigate the pyrolysis efficiency and the mechanism of electric field modulation at different temperatures. It elucidates that the pyrolysis reaction activation energy and molecular motion are the key factors affected by the co-effect of temperature and electric field. A filed strength of 10−5 V/Å was shown to increase both the reaction barriers and the probability of collision for JP-10 molecule pyrolysis, which promotes a higher reaction rate in weak electric fields with high-temperature pyrolysis. The DFT calculation was used to analyze the electronic structure and reaction potential of the JP-10 molecule under the electric field, which further discloses the effect mechanism of electric field on the pyrolysis reaction pathway. This study provides a detailed explanation of combined effects of temperature and electric field effect on aviation fuel pyrolysis to enable effective combustion of aviation fuels.

A new electric coupling and its applications on millimeter-wave SIW filter with high selectivity and controllable TZs

In this paper, a novel simple horizontal electric coupling (SHEC) structure is proposed, which only requires a single elliptical ring slot to be etched at the top layer of the substrate between the two adjacent SIW cavities. The working mechanism of SHEC is revealed using the equivalent magnetic current theory. The results indicate that the ring slot is divided into two semi-elliptical slots by the via-hole, and the induced electric fields generated by equivalent magnetic current near the slots enhance the extremely weak electric field intensity at the edge of the SIW cavities, resulting in the formation of electric coupling between the adjacent two cavities. As a verification, a fourth-order SIW filter operating at 27.96 GHz was designed based on the SHEC structure. The filter exhibits high selectivity with sharp roll-off of 114/105 dB/GHz and obtains controllable transmission zeros (TZs) by changing the size of the elliptical slot. Additionally, the proposed SHEC design has a regular via-holes arrangement and does not require etching slot on the bottom layer of the substrate, making it easy to accurately process, integrate, and package, providing a new approach for the design of millimeter-wave filters.

Magnetic-field-induced splitting of Rydberg Electromagnetically Induced Transparency and Autler-Townes spectra in 87Rb vapor cell.

We theoretically and experimentally investigate the Rydberg electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting of 87Rb vapor under the combined influence of a magnetic field and a microwave field. In the presence of static magnetic field, the effect of the microwave field leads to the dressing and splitting of each mF state, resulting in multiple spectral peaks in the EIT-AT spectrum. A simplified analytical formula was developed to explain the EIT-AT spectrum in a static magnetic field, and the theoretical calculations agree qualitatively with experimental results. The Rydberg atom microwave electric field sensor performance was enhanced by making use of the splitting interval between the two maximum absolute mF states separated by the static magnetic field, which was attributed to the stronger Clebsch-Gordon coefficients between the extreme mF states and the frequency detuning of the microwave electric field under the static magnetic field. The traceable measurement limit of weak electric field by EIT-AT splitting method was extended by an order of magnitude, which is promising for precise microwave electric field measurement.

Mixed-Valence Bridged Norbornylogous Compounds as Switchable Cells for Molecular Quantum Cellular Automata: A Compromise between High Polarizability and Low Power Dissipation.

In this article, we analyze power dissipation in the nonadiabatic switching event in mixed-valence (MV) molecular cells of quantum cellular automata (QCA) in combination with a key functional property of cells such as polarizability in the applied electric field. We demonstrate that although the requirements for a strong nonlinear response of the cell to the applied electric field and low heat release are competing from the point of view of molecular parameters, this by no means can be regarded as an insurmountable obstacle for achieving functional advantages and possibility of practical application of QCA. The general theoretical consideration is applied to the series of MV compounds exemplifying electric field-switchable MV molecules, which include oxidized norbornadiene [C7H8]+ (I) and its polycyclic derivatives [C12H12]+ (II), [C17H16]+, (III), [C27H24]+ (IV), and [C32H28]+ (V). Based on the results of high-level ab initio calculations performed for the series of compounds with variable length of the bridge connecting redox groups, we show that strongly localized cation radicals with long bridges can be easily polarized even by a fairly weak electric field. This ensures quite low power dissipation, which is shown to coexist with a rather strong nonlinear cell-cell response. We thus conclude that consideration of the series of MV dimers with controllable electron transfer provides a reasonable way to design molecule-based QCA cells with the required properties.

The effect of fatty acids, ionic strength, and electric fields on the microscopic dynamics of BSA aggregates

This paper presents the microscopic dynamics of the concentrated suspensions of bovine serum albumin (BSA) proteins and their aggregates by dynamic light scattering (DLS) experiments. The effects of fatty acids binding to BSA, as well as the ionic strength and weak electric field, are discussed for affecting the stability of BSA suspensions against calcium-induced aggregation. By variation of the ionic strength, in the absence of an external electric field, DLS experiments show that monomer–BSA interactions (in the essentially fatty acid-free case) are overall repulsive but that, nevertheless, aggregation occurs to some extent. Also, the diffusive properties of different types of BSA are explored under an applied low-AC electric field by means of in situ electric small-angle depolarized DLS experiments, which reveal a significant decrease of the translational BSA–monomer diffusion coefficient with increasing frequency, while the aggregates indicate orientational motion via rotation on applying an electric field. These observations are interpreted in terms of (localized) orientation interactions obtained as oscillations in the intermediate scattering correlation function, as well as the anomalous slower relaxations as resulting in effective (collective) dynamics between monomeric BSA and their protein aggregates.

Numerical analysis of electro-thermo-convection in a differentially heated square cavity with electric conduction

Natural convection with an electric field in the classic differentially heated square cavity is numerically studied. The electric conduction model for the generation of free space charges, which applies to weak and moderate electric field with weakly conducting liquids, is specially considered. The whole set of governing equations is implemented in the open-source finite-volume framework of OpenFOAM. Thorough investigation has been undertaken to analyze the thermal and flow characteristics of electro-thermo convection. The results reveal that the introduction of an electric field leads to a suppressive influence on flow motion across all considered Rayleigh numbers (Ra), aligning with recent experimental findings. This effect becomes more pronounced with increasing conduction number (C 0), resulting in the reduction of flow intensity and a thicker thermal boundary layer. Consequently, heat transfer is subdued due to the electric field, causing a decrease in the Nusselt number (Nu) as C 0 increases. To elucidate the mechanism how the electric field impacts natural convection, the torques induced by the electric and buoyancy forces are computed. Higher C 0 will lead to a lower buoyancy torque and stronger electric torque, where the electric torque is opposite to the buoyancy torque, thus the weaker flow strength is shown at higher C 0. Finally, to quantify the reduction in heat loss, the relative Nusselt number (Rnu) is introduced. It is found that there is a critical Ra corresponding to minimal Rnu, and for the parameters considered in this study, the minimum Rnu of 0.563 is observed at C 0 = 0.2 and Ra = 1.2 × 104. For large Ra, the Rnu almost keeps constant with increasing Ra.

A Dirac-material-inspired non-linear electrodynamic model

We propose and study the properties of a non-linear electrodynamics (ED) that emerges inspired on the physics of Dirac materials. This new electrodynamic model is an extension of the one-loop corrected non-linear effective Lagrangian computed in the work of Keser et al (2022 Phys. Rev. Lett. 128 066402). In the particular regime of a strong magnetic and a weak electric field, it reduces to the photonic non-linear model worked out by Keser et al (2022 Phys. Rev. Lett. 128 066402). We pursue our investigation of the proposed model by analyzing properties of the permittivity and permeability tensors, the energy–momentum tensor and wave propagation effects in presence of a uniform magnetic background. It is shown that the ED here presented exhibits the vacuum birefringence phenomenon. Subsequently, we calculate the lowest-order modifications to the interaction energy, considering still the presence of a uniform external magnetic field. Our analysis is carried out within the framework of the gauge-invariant but path-dependent variables formalism. The calculation reveals a screened Coulomb-like potential with an effective electric charge that runs with the external magnetic field but, as expected for Dirac-type materials, the screening disappears whenever the external magnetic field is switched off.

Modeling of voltage-limiting kinetics in two-layer varistor–posistor structures

PurposeThe purpose of this study is to model the dependences of the output voltage, temperature, current and electrical power dissipation of a voltage limiter based on a two-layer varistor–posistor structure on time and analysis the influence of operating modes and design parameters of such a limiter on these characteristics.Design/methodology/approachThe behavior of the limiting voltage, temperature and other parameters of the voltage limiter when an input constant overvoltage is applied is studied by the simulation method. The voltage limiter was a two-layer construction. One layer was a zinc oxide ceramic varistor. The second layer was a posistor polymer composite with a nanocarbon filler of PolySwitch technology.FindingsThe output voltage across the varistor layer decreases and reaches some fixed value related to its breakdown voltage after applying a constant overvoltage to the structure over time. The temperature of the structure increases to some steady state value, while the current decreases significantly. The amplitude of the transient current pulse increases, its duration and energy of the transient process decrease with increasing overvoltage. An increase in the internal resistance of the overvoltage source can cause a decrease in the amplitude and an increase in the duration of transient currents.Originality/valueThe ranges of values for the activation energy of conduction of the varistor layer in weak electric fields, the intensity of heat exchange between the structure under study and the environment are determined to ensure the stable operation of this structure as a voltage limiter. The results obtained make it possible to select the necessary parameters of the indicated structures to ensure the required operating modes of the voltage limiter for various applications.

Nonlinear and relaxation processes in piezoceramics in weak electric fields

We study the effects of piezoelectric hysteresis and relaxation induced by a weak constant electric field in ferroelectric ceramics. Using the piezoelectric resonance analysis method and program, precision measurements of the impedance spectra for thickness and radial vibrations of thin piezoceramic disks were performed for various polarities of the applied constant electric field and polarization of the piezoceramic. An analysis of the field and time dependences of the complex piezoelectric constants of piezoceramics obtained by processing sequentially measured impedance spectra is carried out, and a physical interpretation of the results is proposed.

Piezoelectric relaxation in piezoceramics in weak electric fields

We study the processes of piezoelectric relaxation that occur in piezoelectric ceramics under the influence of weak constant electric fields. Precise measurements of the piezoresonance spectra of the ferroelectric ceramics of the PZT system at various directions of the applied constant electric field and polarization were performed using the method and program for the analysis of piezoelectric resonance for the radial and thickness resonant vibration modes of piezoceramic disks. A qualitative analysis of the time dependences of the real and imaginary parts of the piezoelectric constants of the studied piezoceramic disks obtained because of mathematical processing of sequentially measured piezoresonance spectra was carried out, and a physical interpretation of the results was proposed.

Piezoelectric Relaxation in Piezoceramics in the Region of Weak Permanent Electric Fields

Piezoelectric Relaxation in Piezoceramics in the Region of Weak Permanent Electric Fields

Adaptive shift of active electroreception in weakly electric fish for troglobitic life

The adaptive-shift hypothesis for the evolution of cave-dwelling species posits that ancestor species in surface habitats had exaptations for subterranean life that were exploited when individuals invaded caves. Weakly electric Gymnotiform fishes, nocturnal South American teleost fishes, have features that appear to be likely exaptations for troglobitic life. These fishes have active electrosensory systems in which fish generate weak electric fields that are detected by specialized electroreceptors. Gymnotiform fishes use their electric fields for navigation, prey capture (scene analysis), and social communication. Although active electrosensory systems appear to be exaptations for troglobitic life, as fish use these systems to “see in the dark”, producing electric fields is energetically costly. Cave habitats, which often are low in resources, may not be able to support such high energetic demands. Eigenmannia vicentespelaea, a species of weakly electric fish that is endemic to the São Vicente II cave in central Brazil, surprisingly generates stronger electric fields than their surface relatives. The increase in strength of electric fields may result simply from differences in size between cave and surface populations, but may also be due to lack of predation pressure in the cave or increases in “sensory volumes” and acuity that improve prey localization and capture. Eigenmannia vicentespelaea exhibits the classical phenotypes of any troglobitic fish: these fish have small to nonexistent eyes and loss of pigmentation. The closest living surface relative, Eigenmannia trilineata, inhabits streams nearby and has eyes and pigmentation. The electrosensory and locomotor behavior of both species of fish were measured in their natural habitats using a grid recording system. Surface Eigenmannia exhibited dramatic circadian changes in social behavior, such as hiding under rocks during the day and foraging in groups at night, while cave Eigenmannia displayed territorial behavior with no apparent circadian modulations. The territorial behavior involved electrical and movement-based interactions that may be a form of boundary patrolling. Electrosocial behavior and scene analysis are mechanistically interlinked because both stem from active sensing tactics.

Nonlinear and Relaxation Processes in Piezoceramics in the Region of Weak Electric Fields

Nonlinear and Relaxation Processes in Piezoceramics in the Region of Weak Electric Fields