Magnetic plasmon mode resonance and power transmission in a nanosandwich waveguide

The magnetic plasmon （MP） modes in the metal-dielectric-metal nanosandwich structure are investigated nu- merically, and the principle of energy resonance in such a resonator is proposed. An equivalent inductance capacitance circuit analysis method is proposed and the results are in agreement with the numerical simulations. Based on the MP resonance in such a structure, a nanosandwich chain waveguide is designed. Gold and silver are chosen as the metal materials. The power transmission e^ciency of the nanosandwieh waveguide can be as high as 0.546 in a specific nanosandwich unit cell, even when the metal absorption loss is large, which is the perspective of the new waveguides and lasers based on MP modes.

Shape Anisotropy and Resonance Mode Guided Reliable Interconnect Design for In-plane Magnetic Logic

Dipole coupled nanomagnets controlled by the static Zeeman field can form various magnetic logic interconnects.However, the corner wire interconnect is often unreliable and error-prone at room temperature. In this study, we address this problem by making it into a reliable type with trapezoid-shaped nanomagnets, the shape anisotropy of which helps to offer the robustness. The building method of the proposed corner wire interconnect is discussed,and both its static and dynamic magnetization properties are investigated. Static micromagnetic simulation demonstrates that it can work correctly and reliably. Dynamic response results are reached by imposing an ac microwave field on the proposed corner wire. It is found that strong ferromagnetic resonance absorption appears at a low frequency. With the help of a very small ac field with the peak resonance frequency, the required static Zeeman field to switch the corner wire is significantly decreased by ~21 m T. This novel interconnect would pave the way for the realization of reliable and low power nanomagnetic logic circuits.

Electrostatic Modes of Dusty Plasmas in a Uniform Magnetic Field

Electrostatic dusty plasma waves in a uniform magnetic field are studied. Unless the magnetic field is extremely strong, the dust particles can hardly be magnetized, while however, electrons and ions are easily done so. Electrostatic modes in such dusty plasmas can then be investigated by making use of the 'moderately magnetized' assumption of magnetized electrons and ions, and unmagnetized dust particles. In a high frequency range, due to the existence of dust component, both frequencies of Lang- muir waves (parallel to the magnetic field) and upper hybrid waves (perpendicular to the field) are reduced. In the frequency range of ion waves, besides the effect on dust-ion-acoustic waves propagating parallel to the magnetic field, the frequency of ion cyclotron waves perpendicular to the magnetic field is also enhanced. In a very low dust frequency range, we find an 'ion-cyclotron- dust-acoustic' mode propagating across the field line with a frequency even slower than dust acoustic waves.

A Simple Mechanism for Generating a Geomagnetic Field

On the basis of the ideal gas model, the polarization of charges in the mantle was obtained, a physical and mathematical model was constructed, and estimated calculations of the dipole mode of the Earth’s magnetic field were performed, taking into account the speed of its angular rotation, the parameters of density and temperature, the chemical composition, the ionization potential, the dielectric constant and the percentage of the main chemical compounds of the mantle substance.

A Substrate Integrated Waveguide Based Filtenna for X and Ku Band Application

In this paper Substrate Integrated Waveguide-basedfiltenna operating at Ku band is proposed.The model is designed on a low loss dielectric substrate having a thickness of 0.508 mm and comprises of shorting vias along two edges of the substrate walls.To realize a bandpassfilter,secondary shorting vias are placed close to primary shorting vias.The dimension and position of the vias are carefully analyzed for Ku band frequencies.The model is fabricated on Roger RT/duroid 5880 and the performance characteristics are measured.The proposed model achieves significant impedance characteristics with wider bandwidth in the Ku band.The model also achieves a maximum gain of 7.46 dBi in the operating band thus making it suitable for Ku-band applications.Substrate Integrated Waveguide(SIW)Structures possess most of the advantages over conventional radiofrequency waveguides since they have high power management capacity with self-consistent electrical shielding.The most noteworthy advantage of SIW,it can able to integrate all the components on the same substrate,both passive and active components.

Types of the jump phenomenon in the angular dependence of the noncollinear exchange bias

Based on the principle of minimal energy and the coherent rotation model, two types of the jump phenomena, complete and incomplete jump phenomenon, are proved to exist in the angular dependence of the exchange bias with noncollinear unidirectional and uniaxial anisotropies. It is found that the transition between complete and incomplete jump phenomena occurs on condition that the exchange-coupling constant exceeds a critical value. Additionally, two different modes of the magnetization rotation, the whole-plane rotation, and the half-plane rotation are present in the magnetization reversal process, and they are dependent on the direction of the external field. Furthermore, the equations of the critical angle, at which orientation the exchange bias field reaches a maximum value and the coercivity disappears, are also derived in this paper. The numerical calculations in this paper are consistent with the relevant experimental observations, indicating that our method to study the angular dependence of the exchange bias as well as the magnetization reversal behaviors is valid. Our discussion about the jump phenomenon, the critical angle, and the modes of the magnetization reversal can explain the observed differences in results between different experiments.

Simulation of Secondary Electron and Backscattered Electron Emission in A6 Relativistic Magnetron Driven by Different Cathode

Prticle-in-cell（PIC） simulations demonstrated that,when the relativistic magnetron with diffraction output（MDO） is applied with a 410 kV voltage pulse,or when the relativistic magnetron with radial output is applied with a 350 kV voltage pulse,electrons emitted from the cathode with high energy will strike the anode block wall.The emitted secondary electrons and backscattered electrons affect the interaction between electrons and RF fields induced by the operating modes,which decreases the output power in the radial output relativistic magnetron by about 15%（10%for the axial output relativistic magnetron）,decreases the anode current by about 5%（5%for the axial output relativistic magnetron）,and leads to a decrease of electronic efficiency by 8%（6%for the axial output relativistic magnetron）.The peak value of the current formed by secondary and backscattered current equals nearly half of the amplitude of the anode current,which may help the growth of parasitic modes when the applied magnetic field is near the critical magnetic field separating neighboring modes.Thus,mode competition becomes more serious.

Nonlocal response of electric and magnetic modes in a silver cuboid dimer

The nonlocal effect on the spontaneous emission of a silver cuboid dimer is investigated using a local analog model. Magnetic as well as electric dipole excitations are introduced to excite different gap modes. The nonlocal response of electric and magnetic modes on various parameters of gap （width and refractive index） are investigated. Unidirectional radiation is achieved by the interaction between electric and magnetic modes in both local and nonlocal models. Compared to local simulations, the resonant wavelength is blue shifted and the spontaneous emission enhancement is weakened in the nonlocal model. The relative shifts of the resonant wavelengths get larger in smaller gaps with a higher refractive index.

Generating scattering dark states through the Fano interference between excitons and an individual silicon nanogroove

Effective interactions between excitons and resonating nanocavities are important for many emerging applications in nanophotonics.Although plasmonic nanocavities are considered promising substitutes for diffraction-limited dielectric microcavities,their practical applications are hindered by large ohmic loss and Joule heating.Other than plasmonic materials,highrefractive-index dielectric nanocavities is a new way to trap light in subwavelength scales.However,studies on the interaction between dielectric nanocavities and excitons are still scarce.Here,for the first time,we demonstrate that the Fano interference between molecular excitons and an individual silicon nanogroove can generate scattering dark modes.By placing J-aggregate excitons into a silicon nanogroove,the leaky magnetic resonant modes filling in the groove can tailor their scattering directivity and reduce the uncoupled radiation decay in a specific direction.This unidirectional‘dark state’brings a new approach to tailor the interaction between excitons and nanocavities without large near-field enhancement.By adjusting the resonant modes,the scattering spectra can change from a Fano asymmetric line shape to a significantly suppressed scattering dip.These findings indicate that silicon nanogrooves can provide a platform for integrated on-chip silicon–exciton hybrid optical systems in the future.

Tunability of Band Gaps of Programmable Hard-Magnetic Soft Material Phononic Crystals

In this paper,the elastic wave band gap characteristics of two-dimensional hard-magnetic soft material phononic crystals(HmSM-PnCs)under the applied magnetic field are studied.Firstly,the relevant material parameters of hard-magnetic soft materials(HmSMs)are obtained by the experimental measurement.Then the finite element model of the programmable HmSM-PnCs is established to calculate its band structure under the applied magnetic field.The effects of some factors such as magnetic field,structure thickness,structure porosity,and magnetic anisotropy encoding mode on the band gap are given.The results show that the start and stop frequencies and band gap width can be tunable by changing the magnetic field.The magnetic anisotropy encoding mode has a remarkable effect on the number of band gaps and the critical magnetic field of band gaps.In addition,the effect of geometric size on PnC structure is also discussed.With the increase of the structure thickness,the start and stop frequencies of the band gap increase.