Classical Electromagnetic Theory Research Articles

Quantum mechanical effects in plasmonic sub-nanometer cavities formed by a tip and substrate structure

Enhancing local field intensity through light field compression is one of the core issues in surface plasmon-enhanced spectroscopy. The theoretical framework for the nanostructure composed of a tip and a substrate has predominantly relied on classical electromagnetic models, ignoring the electron tunneling effect. In this paper, we investigate the plasmonic near-field characteristics in the sub-nanometer cavity formed by the tip and the substrate using a quantum-corrected model. Additionally, we analyze the local electric field and Raman enhancement when hexagonal boron nitride (h-BN) monolayer is used as a decoupling layer for the nanocavity. The results indicate that classical electromagnetic theory fails to accurately describe the plasmonic electric field in smaller sub-nanometer gaps. When the gap is reduced to 0.32 nm, the quantum-corrected model shows that the local electric field in the sub-nanometer cavity is significantly reduced due to the tunneling current, aligning more closely with experimental results. Moreover, adding a high-barrier h-BN layer effectively prevents the occurrence of tunneling current, allowing for a strong local electric field even when the gap is less than 0.32 nm. The calculated maximum Raman enhancement reaches up to 15 orders of magnitude. Our research results provide a deep understanding of quantum mechanical effects in tip-enhanced spectroscopy systems, enabling the potential applications based on quantum plasmons in nanocavity.

Prove That the Half Retarded and Half Advanced Electromagnetic Theory is Equivalent to Maxwell’s Classical Electromagnetic Theory

Prove That the Half Retarded and Half Advanced Electromagnetic Theory is Equivalent to Maxwell’s Classical Electromagnetic Theory

Mass Interaction Principle as a Foundational Framework for Quantum Mechanics

This paper proposes mass interaction principle (MIP) as: the particles will be subjected to the random frictionless Brownian motion by the collision of space time particle(STP) ubiquitous in spacetime. The change in the amount of action of the particles during each collision is an integer multiple of the Planck constant h. The motion of particles under the action of STP is a Markov process. Under this principle, we infer that the statistical inertial mass of a particle is a statistical property that characterizes the difficulty of particle diffusion in spacetime. Within the framework of MIP, all the essences of quantum mechanics are derived, which proves that MIP is the origin of quantum mechanics. Due to the random collisions between STP and the matter particles, matter particles are able to behave exactly as required by the supervisor and shepherd for all microscopic behaviors of matter particles. More importantly, we solve a world class puzzle about the anomalous magnetic moment of muon in the latest experiment,and give a self-consistent explanation to the lifetime discrepancy of muon between standard model prediction and experiments at the same time. Last but not least, starting from MIP, we prove the principle of entropy increasing and clarify the physical root of entropy at absolute zero. Within the framework of MIP, we comprehensively discussed the Copenhagen interpretation. It leads to an important conclusion that Copenhagen interpretation is unnecessary for the quantum mechanical system. We found that Maxwell’s classical electromagnetic theory is applicable to the microscopic world not as previously thought. The key is that Brownian motion and classical electromagnetic theory must be combined together to completely solve the problem of electrons outside the nucleus not radiating electromagnetic waves.

Temperature dependence of optical properties for thermoplastic composite prepreg during laser in-situ consolidation

The optical properties of the thermoplastic prepreg play a critical role in influencing heating efficiency during the in-situ consolidation process. This study investigates the temperature-dependent reflectance of the prepreg during laser heating. A reflectance testing device is developed based on an in-situ heating system, and the reflectance of carbon fiber/PEEK prepreg is studied from 20 to 500 °C. Through a comparative analysis, the reflectance of pure PEEK films and carbon fibers are individually examined within the same temperature range. The variation in reflectance at different temperatures is explained according to the classical electromagnetic theory. Furthermore, the effect of fiber density on the reflectance of thermoplastic prepreg is explored, and the results indicate that the reflectance of the prepreg decreases from 15.65 % to 11.80 % as the temperature rises from 20 °C to 500 °C, which can be primarily attributed to the decline in carbon fiber reflectance with increasing temperature.

Pure TE and TM modes in the metallic waveguide filled homogeneously with fully anisotropic and lossless medium

AbstractThis letter gives a sufficient condition for the existence of the pure transverse electric (TE) and transverse magnetic (TM) modes in the metallic waveguide filled with a homogeneous, fully anisotropic and lossless medium. The condition is a relation between the permittivity and permeability tensors of the fully anisotropic medium. The theory given in the letter is an extension of the classic electromagnetic waveguide theory. Furthermore, a mixed spectral element method is applied to simulate this type of anisotropic waveguide problem. At last, a numerical experiment shows that the sufficient condition supported in the letter does confirm the existence of the pure TE and TM modes in the anisotropic waveguide.

Investigation of the infrared radiation characteristics modulation mechanism of titanium dioxide composite yttria-stabilized zirconia ceramics

Yttria stabilized zirconia (YSZ) presents a promising option for infrared camouflage applications due to its lower emissivity within the 3–5 μm waveband. Nevertheless, its emissivity increases within the 8–14 μm waveband, which is attributed to lattice vibration-induced absorption characteristics, combined with an extended Christiansen wavelength (K-point). In this study, we regulate YSZ’s infrared radiation performance in the 8–14 μm band by combining a material with lower infrared emissivity in the 8–14 μm band and lower lattice resonance frequencies such as titanium dioxide (TiO2) based on lattice vibration theory and classical electromagnetic theory. The results showed that as the TiO2 content increases, the emissivity of the composite ceramic block remains relatively stable in the 3–5 μm band. Notably, With a TiO2 content of 80 %, the emissivity within the 8–14 μm band decreases from 0.55 to 0.48 and within the 5–8 μm band increases from 0.33 to 0.41, the K-point of ceramics shifted from 12.8 μm to 11.8 μm. It provides an effective approach for modulating the infrared emissivity and K-point of YSZ.

High-order cavity coupled plasmon polaritons in resonant cavity-monolayer MoS<sub>2</sub> system

Compared with graphene, two-dimensional (2D) transition metal sulfides, represented by mono-/few-layer MoS<sub>2</sub>, have tunable non-zero bandgap, and thus their applications in optoelectronic devices are more advantageous. By using classical electromagnetic theory and finite element method (FEM), we investigate the cavity coupled plasmon polaritons (CCPPs) formed through the coupling between cavity modes in a resonator and plasmons in monolayer MoS<sub>2</sub>, particularly calculate and verify the properties of the high-order CCPPs. In previous work, it was demonstrated that the substrates, defects, and polycrystalline grains of the CVD grown monolayer MoS<sub>2</sub> usually induce weak electron localization, which leads to the deviation from the Drude model based on the approximation of free electron gas. Therefore, here we use the Drude-Smith model with characteristic parameters obtained experimentally to describe the optical conductivity of monolayer MoS<sub>2</sub> in our theoretical calculation and simulation. Then, we not only derive and solve the dispersion equations of the high-order CCPPs, but also verify the existence and analyze the properties of these high-order modes. Specifically, there are three types of CCPPs in the asymmetric cavity-monolayer MoS<sub>2</sub> system, i.e. the FP-like-modes (FPLMs), the surface-plasmon-like modes (SPLMs), and the quasi-localized modes (QLMs). Among them, the FPLMs and QLMs can support high-order modes whereas the SPLMs only support the fundamental modes. According to our model, we calculate the wave localization properties for the 7th-order and 8th-order FPLM, the 3rd-order and 6th-order QLM, and the SPLM. These theoretical results are in good agreement with the simulation results. Moreover, the effects of weak electron localization are also shown by comparing the field distributions of the CCPPs based on the Drude model with those based on the Drude-Smith model. It is found that weak electron localization can reduce the coupling between the cavity modes and the plasmons in monolayer MoS<sub>2</sub>. These results can deepen our understanding of the excitation of plasmons in 2D materials as well as the modulation of their properties. Furthermore, the theoretical model can also be extended to other plasmonic systems related to low-dimensional and topological quantum materials.

High-temperature superconductivity mechanism and an alternative theoretical model of Maxwell’s classical electromagnetism theory

In the 21st century, understanding the mechanism of high-temperature superconductivity has emerged as a pinnacle achievement in condensed matter physics, capturing the lifelong interest of numerous physicists. This paper endeavors to offer a theoretical elucidation for this mechanism, advancing the broader field of physics. Recognizing that high-temperature superconductivity is an aspect of condensed matter physics — underpinned by Maxwell’s classical electromagnetic theory — we turn to theoretical mechanics and field theory, which are foundational perspectives in the contemporary scientific era. By framing Maxwell’s classical electromagnetic theory within the context of theoretical mechanics and field theory, this paper not only sheds light on the mechanism of high-temperature superconductivity but also recasts Maxwell’s theory within a purer theoretical mechanics and field theory domain. This represents a paradigmatic shift and cognitive transformation in physics. Furthermore, leveraging this theoretical mechanics and field theory interpretation of electromagnetic phenomena, we discern that electromagnetic phenomena can be more aptly explained without resorting to the concepts of charges and electric fields, leading to a reinterpretation of Coulomb’s law. We propose that protons and electrons might exist as entities devoid of charge-specific attributes and negate the possibility of a strongly correlated particle system within them.

From quantum electrodynamics to a geometric gauge theory of classical electromagnetism

A relativistic version of the correspondence principle, a limit in which classical electrodynamics may be derived from quantum electrodynamics (QED), has never been clear, especially when including gravitational mass. Here we introduce a novel classical field theory formulation of electromagnetism, and then show that it approximates QED in the limit of a quantum state which corresponds to a classical charged continua. Our formulation of electromagnetism features a Lagrangian which is gauge invariant, includes a classical complex field from which a divergenceless four-current may be derived, and reproduces all aspects of the classical theory of charged massive continua without any quantum effects. Taking a geometric approach, we identify the four-current as being in the direction of extremal phase velocity of the classical field; the field equations of motion determine this phase velocity as being equal to the mass, which makes the rest density proportional to the squared modulus of the field.

Quantitative evaluation of IR and corresponding VCD spectra

Classical electromagnetic theory applied to infrared (IR) and vibrational circular dichroism (VCD) spectra of chiral compounds can provide useful insights, such as the fact that the area of all bands of wavenumber-normalized absorbance above zero must be the same as the area below zero. Additionally, dispersion analysis based on wave optics and dispersion theory, which was extended by Born and Kuhn to include chiral substances, can be used to quantitatively describe the dielectric function and the chiral admittance functions that shape IR and VCD spectra. For dispersion analysis, pairs of coupled oscillators, with five different kinds of parameters, namely oscillator strength, damping, oscillator position, vertical distance between coupled oscillators, and the coupling constant are used to model the dielectric functions and chiral admittance functions. We report the results of such an analysis for α-Pinene and Propylene oxide. For most bands, the oscillator model using two coupled oscillators is sufficient to achieve a good correspondence between experimental and modelled data.

Entangled Photon Anti-Correlations Are Evident from Classical Electromagnetism

For any experiment with two entangled photons, some joint measurement outcomes can have zero probability for a precise choice of basis. These perfect anti-correlations would seem to be a purely quantum phenomenon. It is, therefore, surprising that these very anti-correlations are also evident when the input to the same experiment is analyzed via classical electromagnetic theory. Demonstrating this quantum–classical connection for arbitrary two-photon states and analyzing why it is successful motivates alternative perspectives concerning entanglement, the path integral, and other topics in quantum foundations.

Dispersive surface-response formalism to address nonlocality in extreme plasmonic field confinement

Abstract The surface-response formalism (SRF), where quantum surface-response corrections are incorporated into the classical electromagnetic theory via the Feibelman parameters, serves to address quantum effects in the optical response of metallic nanostructures. So far, the Feibelman parameters have been typically obtained from many-body calculations performed in the long-wavelength approximation, which neglects the nonlocality of the optical response in the direction parallel to the metal–dielectric interface, thus preventing to address the optical response of systems with extreme field confinement. To improve this approach, we introduce a dispersive SRF based on a general Feibelman parameter d ⊥(ω, k ‖), which is a function of both the excitation frequency, ω, and the wavenumber parallel to the planar metal surface, k ‖. An explicit comparison with time-dependent density functional theory (TDDFT) results shows that the dispersive SRF correctly describes the plasmonic response of planar and nonplanar systems featuring extreme field confinement. This work thus significantly extends the applicability range of the SRF, contributing to the development of computationally efficient semiclassical descriptions of light–matter interaction that capture quantum effects.

Energy Flow and Photons from Primary Coil to Secondary Coil of Transformer

The author proposed the mutual energy theorem in 1987 and the mutual energy flow theory since 2017. The theory of mutual energy has an axiom more than Maxwell’s equations, that is, the law of conservation of energy. The conservation of energy law is not Poynting’s theorem, but an extension of the mutual energy theorem. Because of this new axiom, the new axiom conflicts with Poynting’s theorem. In fact, it is also a conflict with Maxwell’s electromagnetic theory. The author believes that the law of conservation of energy should be adhered to, so Poynting’s theorem or Maxwell’s classical electromagnetic theory should be appropriately modified. These works have been completed by the author in other papers. Recently, when studying the magnetic quasi-static electromagnetic field, the author found that the electromagnetic energy conservation law proposed by the author can be strictly proved in the magnetic quasi-static electromagnetic field environment. This is a great inspiration to the author. Based on the theory of magnetic quasi-static electromagnetic field, the author strictly proves the law of conservation of energy (mutual energy theorem) and the mutual energy flow theorem proposed by the author, and applies this theory to calculate the energy flow from the primary coil to the secondary coil of transformer. In order to simplify the problem, the author only calculates the mutual energy flow between two parallel current elements. The calculation results show that the mutual energy flow is generated on the primary coil and annihilated on the secondary coil. The properties of mutual energy flow are completely consistent with those of photons. It is also close to the photon model in Cramer’s transactional interpretation of quantum mechanics. The author believes that the transmitting antenna is consistent with the primary coil of the transformer, and the receiving antenna is consistent with the secondary coil of the transformer. The author believes that for the theoretical generalization from magnetic quasi-static electromagnetic field to radiated electromagnetic field, the law of conservation of energy, the theorem of mutual energy flow should guarantee and the time average value of self energy flow should be kept at zero. In this way, a new electromagnetic field theory which is different from Maxwell’s electromagnetic theory is obtained. Maxwell’s electromagnetic field theory adds displacement current, but it makes formulas such as the energy conservation law problematic in the case of radiation field. Maxwell’s electromagnetic field theory and mutual energy theory provide the same electric field, but the far-field part of the magnetic field (i.e. radiated electromagnetic field) is different. In addition, the electromagnetic mutual energy theory proposed by the author believes that the charge of the receiver produces an advanced wave. Advanced wave violates today’s causality, but it is an objective physical existence.

TESLA’S INVENTIONS IN PHYSICS AND HIS ENGINEERING SPIRIT

The article describes Tesla’s inventions in physics. Tesla’s engineering spirit is compared to M. Faraday’s and A. A. Michelson’s spirit of discovery in electromagnetism. Tesla’s unfinished investigative journey, from great experiments in electrical technology and radio technology to the physical theories he derived from them, are examined historically and scientifically. Several discoveries and individual experiments are described that were signifcant in the subsequent development of accelerator technology, as well as Tesla’s monopole antenna for high power and long-range electromagnetic waves, in which the principle of Tesla’s transformer is applied. Within the framework of classical electromagnetic theory, calculations and modern analysis of the system for the study of Tesla’s model of the long-distance wireless transmission of electromagnetic energy or information are presented, demonstrating the scientific basis for Tesla’s ideas. The coverage of Tesla’s inventions and contributions in the physics and electrical engineering curricula at the University of Zagreb is reviewed, especially in textbooks and other works by Ivan Supek, Vatroslav Lopašić and Tomo Bosanac. An interpretation is offered of Tesla’s interest in Goethe’s poetry, which provided an impetus for his inventions and desire for knowledge.

Спектральная излучательная способность переходных металлов X группы в области точки плавления

An experimental study of the normal spectral emissivity of technical nickel, palladium and platinum in the solid polished and liquid phases near the melting points was carried out by the radiation method. The emission measurement was recorded by the bandwidth of the applied narrowband filters. The dependence of metal emission on the wavelength in the range of the radiation spectrum 0.26−10.6 µm is obtained. A comparative analysis with the literature data of other authors is carried out. A theoretical calculation of the emission is given according to the classical electromagnetic theory — Hagen 's formula and Rubens.

Spectral emissivity of transition metals of the X group in the melting point region

An experimental study of the normal spectral emissivity of technical nickel, palladium and platinum in the solid polished and liquid phases near the melting points was carried out by the radiation method. The emission measurement was recorded by the bandwidth of the applied narrowband filters. The dependence of metal emission on the wavelength in the range of the radiation spectrum 0.26-10.6 μm is obtained. A comparative analysis with the literature data of other authors is carried out. A theoretical calculation of the emission is given according to the classical electromagnetic theory Hagen's formula and Rubens. Keywords: normal spectral emissivity, melting range, nickel, palladium, platinum, wavelength.

On the rub-impact force, bifurcations analysis, and vibrations control of a nonlinear rotor system controlled by magnetic actuator integrated with PIRC-control algorithm

This article presents the Proportional Integral Resonant Controller (PIRC-controller) as a novel control strategy to suppress the lateral vibrations and eliminate nonlinear bifurcation characteristics of a vertically supported rotor system. The proposed control algorithm is incorporated into the rotor system via an eight-pole electromagnetic actuator. The control strategy is designed such that the control law (PIRC-controller) is employed to generate eight different control currents depending on the air-gap size between the rotor and the electromagnetic poles. Then, the generated electrical currents are utilized to energize the magnetic actuator to apply controllable electromagnetic attractive forces to suppress the undesired lateral vibrations of the considered rotor system. According to the suggested control strategy, the whole system can be represented as a mathematical model using classical mechanics' principle and electromagnetic theory, in which, the rub-impact force between the rotor and the stator is included in the derived model. Then, the obtained discrete dynamical model is analyzed using perturbation techniques and validated numerically through bifurcation diagrams, frequency spectrums, Poincare maps, time responses, and steady-state whirling orbit. The obtained results illustrate that the proposed control algorithm can mitigate the nonlinear vibration and eliminate the catastrophic bifurcations of the rotor system when the control gains are designed optimally. In addition, the system dynamics are analyzed when the rub-impact occurrence between the rotor and the pole housing is unavoidable. The acquired results revealed that the system may perform periodic-1, periodic-n, or quasiperiodic motion with one of two oscillation modes depending on both the impact stiffness coefficient and the dynamic friction coefficient.Article HighlightsNonlinearity dominates the uncontrolled rotor response, where it suffers from the jump phenomenon and multiple solutions.The proposed controller forces the Jeffcott rotor to respond as a linear system with small oscillation amplitudes.The rotor oscillates with full-annular-rub or partial-rub-impact mode when rub-impact occurs between the rotor and stator.

Numerical Investigation on ELF Electromagnetic Field Distribution of Pipeline Robot Tracking and Positioning System Using UAV

Pipeline robot, as a new type of equipment for pipeline operations such as pigging and detection, will play an increasingly important role in the operation and maintenance of oil and gas pipeline networks. The tracking and positioning technology during its operation process is one of the essential topics to improve the operating performance of pipeline robots and eliminate potential pipeline accidents. This paper presents the overall design of the wireless tracking and positioning system for pipeline robots based on extremely low frequency (ELF) electromagnetic method using the unmanned aerial vehicle (UAV). Starting from the classical electromagnetic theory, a mathematical model for the distribution of ELF electromagnetic field in buried metal pipeline environment is established. According to the characteristics of ELF electromagnetic wave transceiver and the model based on classical theory, the equivalent magnetic dipole transmission model is deduced. Based on the equivalent model, the attenuation characteristics of the ELF electromagnetic wave in the external space of the pipeline are analyzed by numerical simulation. The influence of the geometrical dimensions, environmental and working parameters, and other factors on the electromagnetic field intensity outside the pipeline is given at the same time. Finally, the distribution of ELF electromagnetic field in pipeline environment is discussed for horizontal-laying pipeline and inclined-laying pipeline, and the tracking method of pipeline robot is proposed on this basis. The proposed scheme is practical and effective, and it is suitable for real-time tracking and positioning of robot working in the pipelines whose slope is no more than 60 degrees with known or unknown distribution.

The Contradictions in Poynting Theorem and Classical Electromagnetic Field Theory

When studying the energy principle of N current elements, the author found that the Poynting’s theorem of N current elements is very similar to the principle of mutual energy, except that the subscript of the summation symbol is different. Because the mutual energy principle of N current elements and Poynting’s law of N current elements are all energy conservation laws, the author considers that they should be the same. Due to this consideration, the author found that the self-energy flow should not transfer energy. Self-energy flow is the energy flow corresponding to the Poynting vector of a current element, but this energy flow is not zero for any antenna. The author believes that this is a loophole in classical electromagnetic theory. The author’s previous solution was to add a time-reversal wave to Maxwell’s theory. This paper studies this problem through the electromagnetic field of plane-sheet current. It is found that the magnetic field calculated by Maxwell’s equations is still the magnetic field generated by the current itself, but the electric field calculated by Maxwell’s equation is actually the advanced wave generated by the environment of the current.

Design of locally enhanced electric field in dielectric loaded rectangular resonator for quantum microwave measurements

Rydberg-atom electrometers have the remarkable advantages of self-calibration and high sensitivity. Based on the classical electromagnetic theory, a localized electric field enhancement structure of a hybrid rectangular resonator (RR) is proposed to improve the sensitivity of quantum microwave measurement. It should be noted that the prototype of the hybrid RR is fabricated and measured at 9.925 GHz. The results of full-wave simulations show that the uniform and high electric field enhancement in the TE101 fundamental mode is realized. The transient process of resonance is simultaneously simulated, and the time to settle steady state is given as about 104 ns. As indicated through experimental results that the structure can reach 24 dB (enhancement factor of 15.8). As a result, the method proposed in this study, based on atomic measurement capabilities, enables us to improve the measurement sensitivity further and promotes the practical development of quantum microwave measurement technology.