Solid-state Plasma Research Articles

A novel reconfigurable electromagnetically induced transparency based on S-PINs

In this paper, a tunable electromagnetically induced transparency (EIT) based on S-PINs is theoretically analyzed. Unit cell of the structure consists of a cutwire (CW), split ring resonator (SRR), and solid state plasma (SS plasma) patches which are composed of S-PIN array. The destructive interference between the CW and SRR results in a narrowband transparency window accompanied with strong phase dispersion. The proposed design can obtain a tunable EIT with different frequencies range from 12.8 GHz to 16.5 GHz in a simple method by switching these S-PINs on or off selectively. The related parameters of the S-PIN such as the size, carrier concentration, and volt-ampere characteristics have been studied theoretically. The interaction and coupling between two resonators are investigated in detail by the analysis of the current distribution and E-field strength as well. The research results provide an effective way to realize reconfigurable compact slow-light devices.

Wakefield in solid state plasma with the ionic lattice force

The advent of the path to a single cycle X-ray laser pulse via thin film compression and the relativistic compression enables laser wakefield acceleration in solid materials. We study the collective interaction of the X-ray laser pulse with the solid-state plasma, including ultrafast polariton effects, giving rise to TeV/cm wakefields with highly increased critical density. Our particle-in-cell computational analysis delineates wakefield effects and polariton dynamics. We show that a good quality wakefield can be excited even in the presence of the lattice force and the electron acceleration process is not influenced by polaritons. The applications and implications of the ultrafast wakefield and ultrafast plasmonics are discussed.

Reconfigurable Yagi-Uda antenna based on a silicon reflector with a solid-state plasma

This paper describes the fabrication and characterization of a reconfigurable Yagi-Uda antenna based on a silicon reflector with a solid-state plasma. The silicon reflector, composed of serially connected p-i-n diodes, forms a highly dense solid-state plasma by injecting electrons and holes into the intrinsic region. When this plasma silicon reflector is turned on, the front-realized gain of the antenna increases by more than 2 dBi beyond 5.3 GHz. To achieve the large gain increment, the structure of the antenna is carefully designed with the aid of semiconductor device simulation and antenna simulation. By using an aluminum nitride (AlN) substrate with high thermal conductivity, self-heating effects from the high forward current in the p-i-n diode are efficiently suppressed. By comparing the antenna simulation data and the measurement data, we estimated the conductivity of the plasma silicon reflector in the on-state to be between 104 and 105 S/m. With these figures, silicon material with its technology is an attractive tunable material for a reconfigurable antenna, which has attracted substantial interest from many areas, such as internet of things (IoT) applications, wireless network security, cognitive radio, and mobile and satellite communications as well as from multiple-input-multiple-output (MIMO) systems.

Experimental and Theoretical Study of Optical Antennas Formed from ZnO Nanorods Coated with a Thin Silver Film

A new design of an optical antenna formed from a ZnO nanorod coated with a thin metallic film is proposed. Arrays of ZnO nanorods coated with a thin silver film and highly oriented perpendicular to the substrate have been fabricated using carbothermal synthesis and magnetron sputtering. The problems of diffraction of electromagnetic waves by a single metal–dielectric nanooscillator located at the interface between dielectrics and on a 2D periodic array have been solved. Calculated electrodynamic characteristics of the optical nanoantennas of different lengths have been compared with experimental data. A new optical metal–dielectric diffraction grating absorbing almost 100% of the energy falling onto it at the resonance of the surface wave propagating along the metal (solid state plasma)/dielectric interface has been theoretically investigated.

PLASMA TECHNOLOGIES FOR THE PROTECTION OF RADIO ELECTRONIC MEANS FROM EXPOSURE TO HIGH–POWER ELECTROMAGNETIC RADIATIONS WITH ULTRASHORT PULSE DURATION

The urgency of the improvement of methods and means of protection of radio electronic means (REM) due to the development and application of high–power electromagnetic radiation (EMR) generators with ultrashort pulses duration (UPD) is substantiated. It is pointed out that it is possible to solve the problem of REM protection by the complex application of plasma technologies using gaseous and modified solid–state media. By analyzing the known achievements in the field of developing effective methods and creating protection facilities for REM, a number of unresolved problems in the field of creation of plasma protection technologies have been determined. The technique of solving the formulated problems is presented and the main relations are obtained to determine the expediency of using the proposed technology in the interests of the REM integrated protection from the powerful EMR UPD. A relation is made for the breakdown criterion in a gaseous plasma medium that relates the value of the breakdown field to the concentration of charged particles determined by the ionization source. The structure of a solid–state plasma medium is described, which can be used as a protective shield. The order of finding the REM screening coefficient is shown, based on the determination of the distribution function of charged particles for finding the main macroscopic properties of plasma by solving the kinetic equation of the Lenard–Balescu equation. A relation is given for the damping coefficient of an electromagnetic wave in solid–state plasma. Numerical estimates are presented in the form of graphs showing the possibility of using plasma technology to protect the REM from a powerful EMR through possible channels of penetration. The discussion of the obtained results is presented and it is indicated on the possibility and prospects of using the proposed technology for REM protection, especially with limitations on the weight dimensions of protection devices

Spark plasma sintering of graphene reinforced silicon carbide ceramics

Abstract Silicon carbide (SiC) ceramics have superior properties in terms of wear, corrosion, oxidation, thermal shock resistance and high temperature mechanical behavior, as well. However, they can be sintered with difficulties and have poor fracture toughness, which hinder their widespread industrial applications. In this work, SiC-based ceramics mixed with 1 wt% and 3 wt% multilayer graphene (MLG), respectively, were fabricated by solid-state spark plasma sintering (SPS) at different temperatures. We report the processing of MLG/SiC composites, study their microstructure and mechanical properties and demonstrate the influence of MLG loading on the microstructure of sintered bodies. It was found that MLG improved the mechanical properties of SiC-based composites due to formation of special microstructure. Some toughening mechanism due to MLG pull-out and crack bridging of particles was also observed. Addition of 3 wt% MLG to SiC matrix increased the Vickers hardness and Young's modulus of composite, even at a sintering temperature of 1700 °C. Furthermore, the fracture toughness increased by 20% for the 1 wt% MLG-containing composite as compared to the monolithic SiC selected for reference material. We demonstrated that the evolved 4H-SiC grains, as well as the strong interactions among the grains in the porous free matrices played an important role in the mechanical properties of sintered composite ceramics.

Nitrogen-doped multiwalled carbon nanotubes decorated with copper(I) oxide nanoparticles with enhanced capacitive properties

We report on the enhanced capacitive properties of a copper(I) oxide nanoparticle (Cu2O NP)-decorated multiwalled carbon nanotube (MWCNT) forest with nitrogen (N) doping. A careful in situ solid-state dewetting and plasma doping method was developed that ensured homogeneous decoration and contamination-free Cu2O NPs with N doping on the nanotube sidewalls. The morphology and structure of the hybrid materials were characterised by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, Raman spectroscopy and X-ray photoemission spectroscopy. The electrochemical performance of the hybrid materials was investigated by cyclic voltammetry and galvanostatic charge/discharge tests in a 0.1 M Na2SO4 electrolyte. The electrochemical tests demonstrated that the Cu2O NP/N-MWCNT electrode exhibits a specific capacitance up to 132.2 F g−1 at a current density of 2.5 A g−1, which is 30% higher than that of the pure MWCNT electrode. Furthermore, the electrode could retain the specific capacitance at 85% stability over 1000 cycles. These observations along with the simple assembly method for the hybrid materials suggest that the Cu2O NP/N-MWCNT could be a promising electrode for supercapacitor applications.

Two dimensional electrical conductivity model of the solid state plasma for SPiN device

Two dimensional electrical conductivity model of the solid state plasma for SPiN device

Formation of a plasma with the determining role of radiative processes in thin foils irradiated by a pulse of the PEARL subpetawatt laser

A superbright X-ray source with a radiation temperature of ~1.2 keV making it possible to create a solid-state plasma whose kinetics is determined by the radiative processes has been implemented under the impact of a 170-TW pulse of the PEARL femtosecond laser facility on an aluminum target with submicron thickness. The diagnostics of the created plasma is performed by X-ray spectral methods using spectral transitions in hollow multicharged ions.

Solid-State Nanosecond-Pulse Plasma Jet Apparatus Based on Marx Structure With Crowbar Switches

Atmospheric-pressure plasma jets (APPJs) are widely used in biomedical treatment, surface modification, and sterilization, among others because of their advantages of simple structure, strong chemical activities, nonthermal effects, and convenient handling. In this paper, a nanosecond-pulse power generator based on Marx circuit is proposed. The apparatus consists of a nanosecond-pulse generator with crowbar switch and a needle-ring structure electrode. The nanosecond-pulse generator is modularly designed with ten stages; MOSFETs are used as the main switch and crowbar switch on each stage. A field-programmable gate array is used to generate two-channel trigger pulse signals to control the turn-on or turn-off of switches. The generator can produce repetitive pulses with output voltages of up to 8 kV, pulsewidth of 100–1000 ns, rise time of less than 30 ns, and pulse repetition frequencies of 1 Hz to 1 kHz. The designed nanosecond-pulse generator and the needle-ring structure electrode are used to produce argon plasma jets into open air, and the experiments show that the nanosecond-pulse generator can sustain stable APPJs. This paper lays a foundation for the further exploration of the biomedical effects of APPJs.

The collision frequency model of the solid state plasma for Si/Si 1−x Ge x /Si SPiN device

Abstract A two dimensional(2D) collision frequency model is developed based on the 2D solid state plasma concentration distribution model and mobility model for a heterogeneous Si/Si 1−x Ge x /Si structure SPiN(Surface PiN) devices, which are the basic radiating elements in the reconfigurable solid state plasma antenna. The lower collision frequency can be achieved when the Ge mole fraction x and applied voltage increase at the temperature T=300 K, and that the basically uniform distribution of collision frequency can be obtained for Ge mole fraction x=0.3. Moreover, radiation efficiency and the maximum gain of the antenna for the different collision frequency have also been studied. The proposed model can be a handful for the designing of the solid state plasma antenna.

Reconfigurable designs for electromagnetically induced transparency in solid state plasma metamaterials with multiple transmission windows

A reconfigurable metamaterial analog electromagnetically-induced-transparency-like (EIT-like) effect is theoretically and numerically demonstrated in this paper. The unit cell is composed of a stimulated circular loop element and an unstimulated arc slot element, which are both constructed by semiconductor. The interaction between the two elements of the unit cell leads to a transparency window, resembling a special quantum optical phenomenon as electromagnetic (EM) induced transparency. The proposed designs can realize a continuously tunable EIT-like effect in a broad frequency range from 2.2 GHz to 3.6 GHz by changing the arc slot angle, while the number of EIT-like transmission windows can be configured by increasing the number of arc slots. This scheme which is constructed by solid state plasma (SSP) metamaterial provides an alternative way to realize the tunable plasmonic sensing and make new kinds of reconfigurable devices.

Microwave tunneling in heterostructures with electromagnetically induced transparency-like metamaterials based on solid state plasma

Interference induced electromagnetic induced transparency (EIT)-like effect has demonstrated the ability to realize narrow transmission resonances within the single-resonator stop band. Due to the limited plasma density in actual devices, only few reports discuss the plasma metamaterials and truncated photonic crystals which support electromagnetically induced transparency. However, solid state plasma realized by some semiconductors have the advantages of higher order plasma density and the characteristics of the reconfiguration and tunability. Here, we conduct a numerical study of the perfect microwave tunneling in heterostructures composed of solid state plasma metamaterials and truncated photonic crystal. There is particular emphasis on the tunability of tunneling frequency by changing plasma frequency in solid state plasma, as well as the electric energy density distributions in heterostructures. It was found that, compared to conventional metal photonic crystal, the reflectance of tunneling mode can be reduced from −25.8 dB to −41.7 dB with an optimized Q-factor. Further study on electric energy density distribution confirms that EM wave in-plane localization originated from the EIT-like solid state plasma, which gives rise to the three-dimensional enhancement of sub-wavelength EM wave localization, is stronger than EM wave confinement along the propagation direction. Owing to the tunability of plasma, the tunneling frequency channel can be adjusted or reconfigured in a certain range without adjusting the geometry of the heterostructure. It suggests the fabrication for highly sensitive dielectric sensing, optical switches, and so on.

Resonant transducers for solid-state plasma density modulation

We have developed transducers capable of modulating the plasma density and plasma density gradients in indium antimonide. These transducers make use of piezoelectric drivers to excite acoustic pressure resonance at 3λ/2, generating large amplitude standing waves and plasma density modulations. The plasma density has been directly measured using a laser diagnostic. A layered media model shows good agreement with the experimental measurements.

External irradiation effect on the growth and evolution of in-flame soot species

External irradiation–soot species interaction is a subject that is of great interest due to its existing and future use in research diagnostics, nanomaterial synthesis and energy generation applications. An assessment of the influence of broadband radiation (ultraviolet to infrared wavelengths) on the evolution of soot species within a laminar ethylene-air flame is therefore performed to improve the fundamental understanding of the interaction process. Radiation at an average flux value of 120 kW/m2 is provided by a solid-state plasma light to the lower region of the flame. Soot samples are collected thermophoretically at flame positions that are close to and downstream from the irradiation location, to assess the effect of external irradiation on the evolution of in-flame soot species. The soot samples are imaged using normal-resolution and high-resolution transmission electron microscopes and the images obtained are analyzed. The application of an external irradiation source is found to increase the soot loading of the flame, and have a pronounced impact on the soot morphology, and influence the in-flame soot growth processes/mechanisms. The effects are also found to persist downstream from the irradiation location. The effects are mainly attributed to the coupling of the broadband irradiation with the soot precursors, for the configurations used.

The quantum pinch effect in semiconducting quantum wires: A bird’s-eye view

Those who measure success with culmination do not seem to be aware that life is a journey not a destination. This spirit is best reflected in the unceasing failures in efforts for solving the problem of controlled thermonuclear fusion for even the simplest pinches for over decades; and the nature keeps us challenging with examples. However, these efforts have permitted researchers the obtention of a dense plasma with a lifetime that, albeit short, is sufficient to study the physics of the pinch effect, to create methods of plasma diagnostics, and to develop a modern theory of plasma processes. Most importantly, they have impregnated the solid state plasmas, particularly the electron–hole plasmas in semiconductors, which do not suffer from the issues related with the confinement and which have demonstrated their potential not only for the fundamental physics but also for the device physics. Here, we report on a two-component, cylindrical, quasi-one-dimensional quantum plasma subjected to a radial confining harmonic potential and an applied magnetic field in the symmetric gauge. It is demonstrated that such a system, as can be realized in semiconducting quantum wires, offers an excellent medium for observing the quantum pinch effect at low temperatures. An exact analytical solution of the problem allows us to make significant observations: Surprisingly, in contrast to the classical pinch effect, the particle density as well as the current density display a determinable maximum before attaining a minimum at the surface of the quantum wire. The effect will persist as long as the equilibrium pair density is sustained. Therefore, the technological promise that emerges is the route to the precise electronic devices that will control the particle beams at the nanoscale.

Influence of Sodium Fluoride Doping on Thermoelectric Properties of BiCuSeO

We examined the effect of NaF doping on the thermoelectric properties of p-type Bi1−xNaxCuSeO1−xFx (x = 0, 0.05, 0.10, 0.15) synthesized by a facile method combining a solid-state reaction and spark plasma sintering. The substitution of Bi3+ by Na+ and O2− by F− led to an enhancement of electrical conductivity and a slight increase in thermal conductivity, while the Seebeck coefficient was slightly affected by the doping. The power factor (2.12 μW cm−1 K−2 at 923 K) and the low thermal conductivity resulted in the dimensionless figure␣of merit ZT 0.42 for Bi0.95Na0.05CuSeO0.95F0.05 at 923 K. The obtained results indicated that ZT was not improved by the double substitution at the bismuth and oxygen sites.

Helicon modes in uniform plasmas. I. Low m modes

Helicons are whistler modes with azimuthal wave numbers. They arise in bounded gaseous and solid state plasmas, but the present work shows that very similar modes also exist in unbounded uniform plasmas. The antenna properties determine the mode structure. A simple antenna is a magnetic loop with dipole moment aligned either along or across the ambient background magnetic field B0. For such configurations, the wave magnetic field has been measured in space and time in a large and uniform laboratory plasma. The observed wave topology for a dipole along B0 is similar to that of an m = 0 helicon mode. It consists of a sequence of alternating whistler vortices. For a dipole across B0, an m = 1 mode is excited which can be considered as a transverse vortex which rotates around B0. In m = 0 modes, the field lines are confined to each half-wavelength vortex while for m = 1 modes they pass through the entire wave train. A subset of m = 1 field lines forms two nested helices which rotate in space and time like corkscrews. Depending on the type of the antenna, both m=+1 and m = −1 modes can be excited. Helicons in unbounded plasmas also propagate transverse to B0. The transverse and parallel wave numbers are about equal and form oblique phase fronts as in whistler Gendrin modes. By superimposing small amplitude fields of several loop antennas, various antenna combinations have been created. These include rotating field antennas, helical antennas, and directional antennas. The radiation efficiency is quantified by the radiation resistance. Since helicons exist in unbounded laboratory plasmas, they can also arise in space plasmas.

Helicons in Unbounded Plasmas.

Helicons are whistler modes with helical phase fronts. They have been studied in solid state plasmas and in discharge tubes where boundaries and nonuniformities are ever present. The present work shows that helicons also exist in unbounded and uniform plasmas, thereby bridging the fields of laboratory and space plasma physics. First measurements of helicon field lines in three dimensional space are presented. Helicons with negative and positive mode numbers can propagate with equal amplitudes.

Cyclotron Frequency Oscillations in Semiconductor Plasma in Modulated Magnetic Field

Radio frequency magnetoplasmic waves known as helicons will propagate in solid-state plasma of semiconductors when a strong magnetic field is applied. Helicons have an exact analogy with a electromagnetic whistler wave which is frequently propagated in the rarefied plasma of the Earth’s ionosphere. In our experiments the modulated magnetic field is being used for excitation of helicons. Physically it means that the semiconductor conductivity and effective dielectrical constant are modulated with the same cyclotron frequency of infrared range. The semiconductor sample is in the form of plae and magnetic field is perpendicular to the surface of the plate. It is shown that in the case of modulated field along with the RF helicon waves the transient cyclotron frequency oscillations exist in the semiconductor plasma. For observation of the cyclotron radiation frequency c the modulation depth about one percent is sufficient. The measurement of c provides an opportunity to determine the masses of electrons and holes in solid-state plasma of semiconductors. The proposed method can be used in the cases of pulse and sinusoidal modulation of the magnetic field. Bibl. 5 (in English; summaries in English, Russian and Lithuanian).