The photonic band gap structures of obliquely incident electromagnetic waves propagating in a one-dimension plasma photonic crystal with collision have been studied on the basis of electromagnetic theory and transfer matrix approach. The dispersion relations for both the transverse electric wave case and the transverse magnetic wave case are deduced. And the photonic band gap structures, with their function dependence on the microplasma layer density, microplasma width, collision frequency, background material dielectric constant, and incident angle, are computed. The results show that there exist two photonic band gap structures in an adsorptive plasma photonic crystal: one is a normal photonic band gap structure and the other is an absorption photonic band gap structure. Parameter dependence of the effects is calculated and discussed.

Lipkin-Meshkov-Glick (LMG) models describe a set of $N$ qubits which are located at the corners of an $N$-dimensional simplex and embedded in an external magnetic field. Because of its high coordinate number, quantum correlations in the models are quite nontrivial. For instance, in the large-$N$ limit, two-site entanglement concurrence vanishes for any magnetic field. Multisite global entanglement and generalized global entanglement also tend to vanish in some quantum regions. We characterize the quantum correlations in the LMG model with multipartite nonlocality. In LMG models with anisotropy in the $x-y$ plane, for any fixed magnetic field, the ground-state nonlocality (denoted by $\mathcal{S}$) is found to scale as ${log}_{10}\mathcal{S}\sim aN+b$, with $a$ and $b$ the fitting parameters. For LMG models which are isotropic in the $x-y$ plane, nevertheless, the nonlocality for each Dicke state scales as ${log}_{10}\mathcal{S}\sim a\frac{1}{N}+b$, with $b>0$. Signals for the quantum phase transitions of the models will also be discussed. These results indicate that multipartite nonlocality captures some key ingredient of the ground-state quantum correlations in the models. In addition to the ground states, we also study multipartite nonlocality in the LMG models at finite temperatures. In the anisotropic models, the thermal stability of the nonlocality at low temperatures is determined by the energy gap. For the isotropic models, nevertheless, as the temperature increases, the nonlocality presents a sharp valley which is followed by a round peak. The behavior is far beyond the above-mentioned “thermal stability vs energy gap” picture. The underlying mechanics is the “contribution inversion” of low-lying energy states in the thermal-state nonlocality $\mathcal{S}\left({\widehat{\rho }}_T\right)$; that is, in a low-temperature region, the first-excited state “defeats” the ground state and plays a dominant role in thermal-state nonlocality.

We investigated the mode transition from volume to surface discharge in a packed bed dielectric barrier discharge reactor by a two-dimensional particle-in-cell/Monte Carlo collision method. The calculations are performed at atmospheric pressure for various driving voltages and for gas mixtures with different N${}_2$ and O${}_2$ compositions. Our results reveal that both a change of the driving voltage and gas mixture can induce mode transition. Upon increasing voltage, a mode transition from hybrid (volume+surface) discharge to pure surface discharge occurs, because the charged species can escape much more easily to the beads and charge the bead surface due to the strong electric field at high driving voltage. This significant surface charging will further enhance the tangential component of the electric field along the dielectric bead surface, yielding surface ionization waves (SIWs). The SIWs will give rise to a high concentration of reactive species on the surface, and thus possibly enhance the surface activity of the beads, which might be of interest for plasma catalysis. Indeed, electron impact excitation and ionization mainly take place near the bead surface. In addition, the propagation speed of SIWs becomes faster with increasing N${}_2$ content in the gas mixture, and slower with increasing O${}_2$ content, due to the loss of electrons by attachment to O${}_2$ molecules. Indeed, the negative O${}_2^{-}$ ion density produced by electron impact attachment is much higher than the electron and positive O${}_2^{+}$ ion density. The different ionization rates between N${}_2$ and O${}_2$ gases will create different amounts of electrons and ions on the dielectric bead surface, which might also have effects in plasma catalysis.

A plasma metamaterial that exhibits negative refraction in the terahertz region of the spectrum has been demonstrated in the present communication. The plasma metamaterial is an uniaxial anisotropic metamaterial which is a multilayer stack of alternating plasma layer and background material. The negative refraction in the terahertz region of the proposed metamaterial is explored. The effects of the losses in plasma, plasma density, plasma filling factor, and dielectric constant of background material on the critical frequency and the band width of negative refraction are examined and discussed.

The spin Hall effect of light (SHEL) is a transport phenomenon where the left- and right-circular components will be split and show a small transverse shift perpendicular to the incident plane when the linear polarized light is incident to a planar dielectric interface. In this paper, we have demonstrated a plasma metamaterial waveguide cladded with dielectrics to explore the characteristics of SHEL. The results show that the plasma metamaterial can behave a dielectric, hyperbolic metamaterial, or a metal depending on the plasma filling factor. We also find that the properties of SHEL are actively tunable and can be enhanced by using the proposed plasma metamaterial waveguide. Meanwhile, the enhanced SHEL can be realized in the whole plasma filling factor range. Moreover, the optimal thicknesses of plasma metamaterial and the resonant angles for huge beam displacements with different plasma filling factors are presented. This simple three-layer structure can be used for yielding meaningful results for studying more complex systems related to SHEL.

Characteristic equations in magnetized plasma with chirality are derived in simple formulations and the dispersion relations for propagation parallel and perpendicular to the external magnetic field are studied in detail. With the help of the dispersion relations of each eigenwave, the author explores chirality-induced negative refraction in magnetized plasma and investigates the effects of parameters (i.e., chirality degree, external magnetic field, etc.) on the negative refraction. The results show that the chirality is the necessary and only one factor which leads to negative refraction without manipulating electrical permittivity and magnetic permeability. Both increasing the degree of chirality and reducing the external magnetic field can result in greater range negative refraction. Parameter dependence of the effects is calculated and discussed.