Field Effect Research Articles

Retraction Note: Effect of Resonant Helical Field (RHF) on Runaway Electrons in Tokamaks

Retraction Note: Effect of Resonant Helical Field (RHF) on Runaway Electrons in Tokamaks

Postmodern AI: A New Vision of Man's Relationship with Technology

This research explores the impact of postmodern artificial intelligence (AI) on philosophy, arts, politics, and ethics. It aims to analyze how AI reflects postmodern thought, focusing on concepts like relativism and multiplicity. The study also investigates AI's potential effects in various fields, including creativity, decision-making, and societal norms. The methodology includes a critical review of existing literature and case studies on AI applications. Key findings reveal that AI in the postmodern era challenges traditional notions of truth, authority, and creativity, while raising ethical concerns about bias, privacy, and job displacement. The research calls for clear ethical frameworks, education initiatives, and human-AI collaboration to address these challenges and ensure a balanced future between technology and humanity.

Investigating vertical charge plasma tunnel field effect transistors beyond semiclassical assumptions

In this paper, we examine the effects of subband quantization on the efficacy of an L-shaped gate vertical dopingless tunneling field-effect transistor. The proposed architecture leverages an intrinsic tunneling interface that is fully aligned with the gate metal, resulting in enhanced electrostatic control. We utilized a two-step numerical simulation approach grounded in the Schrödinger-Poisson equations to evaluate the performance of our proposed device and accurately calculate the ON-state current. Additionally, we assessed the influence of defects at the heterojunction on the performance of our device. Under quantum mechanical assumptions, parameters such as ION = 23.8 µA/µm, SSAVG = 12.03 mV/dec, and the ION/IOFF ratio = 4.88 × 1010 indicate that our structure is a promising candidate for high-performance applications.

Ion-Specific Effects under Electric Fields on Ice Nucleation at the Mica Surface.

Applying external electric fields to mineral surfaces can have a substantial impact on ice nucleation, influencing both climate and atmospheric systems. While earlier studies have demonstrated that electric fields can enhance ice nucleation on nonmineral surfaces, the mechanisms driving heterogeneous ice nucleation (HIN) on mineral surfaces under electric fields with different surface ions remain unclear. In this study, we investigate the ion-specific effects under electric fields on HIN efficiency using mica surfaces containing various cations. Our findings reveal that an upward electric field significantly boosts HIN of water droplets atop Na-mica surfaces, raising the nucleation temperature by approximately 6 °C. In contrast, mica surfaces with other cations or those exposed to a downward electric field show no change in nucleation temperature or HIN efficiency. Molecular dynamics simulations suggest that Na+ ions detach more easily from the mica surface under an electric field, exposing more of the flat mica lattice and thus possibly promoting ice nucleation. This study offers new insights into the ion-specific effects of electric fields on HIN, providing a deeper understanding of the role of cations and electric fields in ice nucleation processes.

The role of the external toroidal magnetic field on the large-angle rotation of magnetic flux ropes

It is accepted that magnetic flux ropes might exhibit large-angle rotation in magnetic configurations, including strong external toroidal magnetic fields. The specific mechanisms leading to rotation still remain elusive, however. We examine the mechanisms by which the external toroidal magnetic field facilitates the flux-rope rotation, and we explore potential alternative rotation mechanisms beyond the effects of sheared fields and kink instability. We performed three-dimensional magnetohydrodynamic simulations to model the eruption of magnetic flux ropes in a magnetic configuration with and without external toroidal magnetic fields. We compared the morphology, the dynamics, the magnetic topology, and the Lorentz force acting on the flux rope. The behavior of flux ropes in two simulations is significantly different. The flux rope that evolved without external toroidal fields successfully erupted was accompanied by minor rotation, and the flux rope that evolved with an external toroidal field was confined by large-angle rotation. The evolution of the magnetic topology, the Lorentz force, and the torque showed distinctive patterns in each scenario. Furthermore, the flux ropes in both simulations displayed observable signs of a drifting footpoint. We reveal that external toroidal magnetic fields facilitate the flux-rope rotation, which in turn releases initial twists and amplifies the lateral Lorentz force exerted on the flux rope. The slipping magnetic reconnection between the flux-rope field lines and sheared-arcade field lines can contribute to the rotation, as does the lateral Lorentz force and the kink instability, which is determined by the initial twist number. Moreover, our result suggests that the initial twist of the flux rope cannot determine the rotation angle. The rotation angle of the flux rope does not strictly increase with the initial twist. The rapid release of the twist number necessitates external toroidal magnetic fields.

Two-Dimensional Polymer Films as a Suitable Platform to Covalent Graft Antibody Receptors in an Electrolyte-Gated Organic Field Effect Transistor Bioassay.

Although organic field effect transistor (OFET)-based biosensors have aroused great interest due to their advantages of easy integration and fast response speed, surface functionalization of the sensing interface to achieve high sensitivity and outstanding selectivity while maintaining or minimizing the effect on the performance of OFETs is still extremely challenging. Herein, a carboxyl-functionalized two-dimensional polymer film (2DP) is prepared by the Langmuir-Blodgett (LB) method, which forms a heterojunction with a polymer semiconductor and is used to covalently bond the prostate-specific antigen (PSA) antibody receptor. The ordered periodic structure of 2DP films arranges active sites regularly, providing a suitable platform for high surface loading of receptors, and the weak van der Waals interaction between the 2DP and the semiconductor minimizes the effect on the mobility of charge carriers. The results confirm that the construction of the van der Waals heterojunction has a slight effect on the electron transport of the semiconductor channel and maintains the minimum distance between target molecules and the charge transport semiconductor. Electrolyte-gated organic field effect transistor (EGOFET) biosensors modified with 2DP films as receptor layers showed excellent selectivity in the detection of PSA, and the detection accuracy (0.22 pg/mL) was much lower than its clinical detection limit of 4 ng/mL. The results of PSA detection in serum samples of clinical prostate cancer patients show that EGOFET biosensors can accurately screen positive samples, which is consistent with the results of the clinical electrochemiluminescence (ECL) method.

Nonvolatile Reconfigurable Transistor via Ferroelectrically Induced Current Modulation.

New logic in memory (LiM) architectures, able to unify memory and logic functionalities into a single component, are highly promising for executing self-learning algorithms such as artificial neural networks (ANNs), with lower energy requirements. The multigated reconfigurable field effect transistor (RFET) is a novel type of logic device that can be fully reconfigured at run-time, promising to be a very versatile platform for logic applications. If equipped with a memory element, then it would represent the ideal building block for LiM-enabling hardware with embedded self-learning capabilities. To reach this goal, here we investigate the integration of a ferroelectric Hf0.5Zr0.5O2 (HZO) layer onto dual top gated RFETs. We demonstrate that HZO polarization charges can be successfully employed to tune the height of the two Schottky barriers, influencing the injection behavior and allowing the selection of the majority carriers, thus defining the transistor mode and switching it between a fully p-type transport to a prevalently n-type one. Moreover, we show that the modulation strength is strongly dependent on the height of the pulse used to polarize the ferroelectric domains, allowing for the selection of different current levels. All the different achievable states show a good retention over time, owing to the stability of the HZO polarization. The limitations of the produced devices are discussed, alongside possible mitigation strategies. The presented results demonstrate that ferroelectric HZO can modulate the carrier injection across Schottky barriers in RFET devices. This approach paves the way for the future realization of a fully optimized nonvolatile RFET, an ideal building block for novel LiM hardware, enabling low-power circuits for ANN execution.

Impact of electric field on donor energy and polarisability in GaAs variant toroidal quantum ring

ABSTRACT This study investigates the electronic properties of a GaAs Variant Toroidal Quantum Ring (VTQR) containing an off-centre donor impurity, focussing on the effect of an external electric field on donor energy and polarisability. Based on the effective mass approximation, we solved the Schrödinger equation using the finite difference method. The results show a typical effect at a toroidal angle of 180 ∘ , where the strength of the electric field leads to a decrease in the donor energy. Intriguingly, at toroidal angles of 90 ∘ and 60 ∘ , the donor energy increases with increasing field strength, indicating improved electron confinement. The probability density distributions shown reveal the location of the electron as influenced by the applied field. Furthermore, polarisability reaches its maximum around an angle of about 80 ∘ for all electric field strengths. This work provides a better understanding of the behaviour of electron in quantum ring systems and suggests potential for the engineering of tunable quantum devices.

Magnetic skyrmion: from fundamental physics to pioneering applications

Skyrmionic devices exhibit energy-efficient and high-integration data storage and computing capabilities due to their small size, topological protection, and low drive current requirements. So, to realize these devices, an extensive study, from fundamental physics to practical applications, becomes essential. In this article, we present an exhaustive review of the advancements in understanding the fundamental physics behind magnetic skyrmions and the novel data storage and computing technologies based on them. We begin with an in-depth discussion of fundamental concepts such as topological protection, stability, statics, and dynamics essential for understanding skyrmions, henceforth the foundation of skyrmion technologies. For the realization of CMOS-compatible skyrmion functional devices, the writing and reading of the skyrmions are crucial. We discuss the developments in different writing schemes such as STT, SOT, and VCMA. The reading of skyrmions is predominantly achieved via two mechanisms: the magnetoresistive tunnel junction TMR effect and topological resistivity. So, a thorough investigation into the skyrmion Hall effect, topological properties, and emergent fields is also provided, concluding the discussion on skyrmion reading developments. Based on the writing and reading schemes, we discuss the applications of the skyrmions in conventional logic, unconventional logic, memory applications, and neuromorphic computing, including a model of a skyrmion-based SNN architecture achieving over 90% accuracy on MNIST and fashion-MNIST datasets. Furthermore, we outline the potential of skyrmion-hosting Majorana zero modes in emerging topological quantum computation and helicity-dependent skyrmion qubits.

Spin-lattice relaxation mechanism of magnetic field effects on singlet fission in amorphous molecular semiconductors.

Singlet fission (SF) in molecular semiconductors is a photophysical process of spontaneous splitting of the excited singlet state into a pair of triplet excitons (TT-pair). This process is usually strongly influenced by spin-selective back geminate TT-annihilation (TTA). Spin selectivity manifests itself in magnetic field effects (MFEs) on both TTA and SF kinetics, the study of which allows us to reveal some specific features of this kinetics. In our work, we analyze the mechanism of MFE generation in TTA and SF processes in amorphous molecular semiconductors. In this mechanism, the MFEs are assumed to be determined by magnetic field dependent spin-lattice relaxation (SLR) in TT-pairs, generated by the zero-field splitting interaction (in T-excitons), fluctuating due to T-exciton hopping over arbitrarily oriented molecules in amorphous semiconductors. The SLR-transitions are described with a semiempirical model, which makes it possible to obtain the SF-kinetic functions in analytical form. The mechanism of SLR-assisted MFEs is found to be very efficient in TTA and SF processes. The obtained results are analyzed in detail and applied to interpret experimentally observed SF-kinetic dependences in various magnetic fields. In particular, it is shown that the proposed model of SLR-generated MFEs enables one to describe the effect of crossing of SF-kinetic functions, corresponding to different magnetic fields.

Unsteady MHD Free Convective Flow of a Micro‐Polar Fluids Over a Vertical Porous Plate in the Presence of Radiation and Chemical Reaction

ABSTRACTObjective of the paper is to investigate the motion of an unsteady free convective MHD flow of a micro‐polar fluid over semi‐infinite vertically moving porous plate in the presence of chemical reaction and thermal radiation. A transverse magnetic field is applied, assuming a low magnetic Reynolds number. We have discussed the effects of heat radiation due to a heat source and first order chemical reaction within the medium. The perturbation method is applied to solve the nonlinear coupled partial differential equations in their dimensionless form, converting them into a system of ordinary differential equations, which are then solved analytically. The effects of magnetic field, medium permeability, buoyancy force, heat source, concentration gradient, Prandtl number, thermal diffusion, heat radiation, and first order chemical reaction on velocity, temperature and concentration are discussed graphically. The graphical representations are generated using MATLAB software. For engineering interest, their effects on skin friction, heat and mass transfer in terms of Nusselt number and Sherwood number are discussed; numerical values are shown in tabular form. The results show that magnetic fields reduce fluid velocity, while thermal radiation decreases temperature, and chemical reactions lower concentration. Radiation increases skin friction and heat transfer, while chemical reactions reduce mass transfer. Findings have relevance in various problems and situations arising with micro‐polar fluidic devices, industrial like petroleum and lubrication, mixing etc.

Theoretical study on fused 1,2,3,4-tetrazine-1,3-dinitroxide derivatives under external electric field.

Considering the excellent properties of 1,2,3,4-tetrazine-1,3-dinitroxides, several types of energetic derivatives have been synthesized from them. Among them, [1,2,5] oxadiazolo [3,4-e] [1,2,3,4]-tetrazine-4,6-Di-N-dioxide (FTDO), 5,7-dinitrobenzo-1,2,3,4-tetrazine-1,3-nitrogen dioxide (DTND), and [1,2,3,4] tetrazino [5,6-e] [1,2,3,4] tetrazine-1,3,8-tetraoxide (TTTO) are considered excellent energetic materials. However, there is limited research on their behavior under electric fields. The effect of electric fields was studied using density functional theory to calculate trigger bond changes, strain energy, chemical reactivity, and surface electrostatic potential. The results indicate that the planar structure of FTDO is more unique than that of DTND and TTTO, and its trigger bond is located at special position. Increased electric field strength can lengthen the trigger bond, increase sensitivity, and reduce strain energy of FTDO. Under a positive electric field, DTND and TTTO have longer trigger bond lengths, increased sensitivity, and increased strain energy, while exhibiting the opposite behavior under a negative electric field. Electric fields can affect the chemical reactivity of the all three derivatives. FTDO is less active under positive electric fields, DTND is more active under both electric fields, and TTTO becomes more active under negative electric fields. Finally, the electric field can expand their absorption spectrum range, affecting electron transfer between fragments. All calculations in this article were completed on Gaussian 16 software. The calculation levels are B3LYP/6-311G**, B3LYP/Def2-TZVPP, and PBE1PBE/6-311G**. Multiwfn and VMD were used for wave function analysis. Electric fields have a strength range of - 0.02 to 0.02 a.u., with a growth gradient of 0.01 a.u.

Assessing the effects of electromagnetic fields generated by submarine power cables on the soft-bottom community: An ecological in-situ study.

This study represents the first in situ investigation into the effects of magnetic fields (MFs) on soft-bottom macrofauna communities, laying the groundwork for further studies to better understand their potential consequences on marine ecosystems. Conducted in the Natural Park of the Strait (Southern Iberian Peninsula), the study measured MFs generated by HVAC cables and assessed their impact on soft-bottom macrofauna communities by comparing areas exposed to MFs with two control areas at different depths. Measured MF intensities were relatively low, with a maximum deviation from background levels of 34nT near the cable, decreasing to 1nT at 250m distance. These intensities are considerably lower than those typically used in laboratory experiments inducing physiological effects (0.1-30mT). Results revealed an increasing pattern of species richness (S) with depth, associated with sediment stability and different sediment characteristics. While analyses did not show significant effects of the magnetic field on macrobenthic communities overall, some indications were observed, such as decreased species richness at the deepest station and community homogenization across depths in the cable area compared to control zones. However, the varying patterns observed across different sites and depths necessitate further investigation, particularly considering the differences in MF intensities between field settings and controlled laboratory environments.

Effect of process parameters and hybrid voltage-wind field on nanosecond laser spiral layer hole-cutting performance for thin stainless steel sheets

Effect of process parameters and hybrid voltage-wind field on nanosecond laser spiral layer hole-cutting performance for thin stainless steel sheets

Numerical assessment of heat transfer and entropy generation of a mixed convection ferrofluid flow under the effect of a non-uniform magnetic field

Numerical assessment of heat transfer and entropy generation of a mixed convection ferrofluid flow under the effect of a non-uniform magnetic field

Enhanced photocatalytic degradation of pollutants on ZnMn2O4-OVs/Bi2MoO6-OVs S-scheme heterojunction: Synergistic effect of built-in electric field and dual oxygen vacancies

Enhanced photocatalytic degradation of pollutants on ZnMn2O4-OVs/Bi2MoO6-OVs S-scheme heterojunction: Synergistic effect of built-in electric field and dual oxygen vacancies

Study on Deposition of Coaxial Electrospinning Fibers by Coaxial Auxiliary Flow Field

Gas-assisted coaxial electrospinning (GACES) is a simple and general method for the mass preparation of coaxial nanofiber membranes, which has great industrial potential. However, in the manufacturing process, due to the bending instability of the jet in the electric field and the pulling effect of the gas flow field, the deposition uniformity of the fiber is still a big problem. Through finite element simulation analysis of the flow field in the manufacturing process and the construction of the jet mechanics model after adding the flow field, the influence mechanism of coaxial auxiliary flow on the fiber deposition area and its uniformity was successfully revealed in this research. Finally, the deposition area and thickness uniformity of coaxial fibers are increased by 3 times (the deposition area: 19.63 cm2 → 78.50 cm2) and 2.34 times (the standard variance: 3 μm2 → 10 μm2) by gas-assisted coaxial electrospinning. At the same time, the coaxial auxiliary gas flow also reduces the coaxial fiber diameter by 36.9% (the average fiber diameter: 241 nm ± 5 nm → 152 nm ± 23 nm) and the distribution range by 66% (the standard variance: 1.5 × 102 nm2 → 51 nm2). This research provides a reliable idea and experimental basis for homogeneous preparation of coaxial nanofiber membranes.

A review of effects of electromagnetic fields on ageing and ageing dependent bioeffects of electromagnetic fields

A review of effects of electromagnetic fields on ageing and ageing dependent bioeffects of electromagnetic fields

Effects of anthropogenic electromagnetic fields used for subsurface oil and gas exploration (controlled-source electromagnetics, CSEM) on the early development of Atlantic haddock (Melanogrammus aeglefinus).

Controlled source electromagnetics (CSEM) uses electromagnetic fields (EMF) to detect oil reservoirs. Atlantic haddock, Melanogrammus aeglefinus, is a commercially important demersal fish species that can potentially be impacted by such surveys due to potential overlap with egg distribution. In this study, haddock eggs were exposed to EMF, replicating CSEM survey conditions in a laboratory. Three different EMF intensities were used to replicate different distances between the EMF source and the organism. Exposures lasted for 15min. A worst-case scenario, i.e. 1h exposure at the highest EMF level was also carried out. None of the treatments caused malformations, mortality or affected hatching of eggs. However, EMF exposure induced tachycardia in newly hatched larvae and reduced the size of their yolk sac reserve. The effect was significant at the lowest EMF intensity (corresponding to 1000m between the EMF source and the exposed subject) and increased with exposure time and intensity.

Enhancing maize seed resistance to chilling stress through seed germination and surface morphological changes using high voltage electrostatic field

The effect of high-voltage electrostatic field (HVEF) on maize seeds’ resistance to chilling injury remains unclear. This study investigates the chemical and spatial changes induced by HVEF at macroscopic and microscopic levels via the combination of physiological assessments and scanning electron microscopy (SEM). Maize samples were categorized into low and normal-temperature groups. At an HVEF strength of 1.6 kV/cm, all indices in the low-temperature group significantly improved relative to the control (P < 0.01), with germination potential, rate, index, and vigor index increasing by 11.7%, 11.2%, 10.5%, and 31.7%, respectively. Root length, shoot length, and dry weight of maize seedlings rose by 20.3%, 19.2%, and 16.6%. Further analysis revealed a 62.7% increase in soluble sugar content in HVEF-treated seeds and the lowest leaching solution conductivity of 1.6 kV/cm. These results demonstrate that HVEF treatment enhances soluble sugar accumulation during seed germination, regulating osmotic balance within the cells. Furthermore, SEM assessed maize microtissue morphology after chilling injury and HVEF treatment. Optimal HVEF treatment resulted in cell wall expansion, enhanced fiber elasticity, reduced interstitial spaces, and swollen cells, indicating improved hydrophilicity and protease activity. This study offers valuable insights into the mechanisms by which HVEF improves seed performance under low-temperature stress.