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Projector-based renormalization approach to electron-hole-photon systems in their nonequilibrium steady state
摘要： We present an extended version of the projector-based renormalization method that can be used to address not only equilibrium but also nonequilibrium situations in coupled fermion-boson systems. The theory is applied to interacting electrons, holes, and photons in a semiconductor microcavity, where the loss of cavity photons into vacuum is of particular importance. The method incorporates correlation and fluctuation processes beyond mean-field theory in a wide parameter range of detuning, Coulomb interaction, light-matter coupling, and damping, even in the case when the number of quasiparticle excitations is large. This enables the description of exciton and polariton formation and their possible condensation through spontaneous phase symmetry breaking by analyzing the ground-state, steady-state, and spectral properties of a rather generic electron-hole-photon Hamiltonian, which also includes the coupling to two fermionic baths and a free-space photon reservoir. Thereby, the steady-state behavior of the system is obtained by evaluating expectation values in the long-time limit by means of the Mori-Zwanzig projection technique. Tracking and tracing different order parameters, the fully renormalized single-particle spectra and the steady-state luminescence, we demonstrate the Bose-Einstein condensation of excitons and polaritons and its smooth transition when the excitation density is increased.
关键词： exciton condensation,nonequilibrium steady state,semiconductor microcavity,projector-based renormalization method,electron-hole-photon systems,Bose-Einstein condensation,polariton condensation
更新于2025-09-23 15:23:52
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Four-Way Spoof Surface Plasmon Polaritons Splitter/Combiner
摘要： Corrugated metal with period grooves supports spoof surface plasmons polariton (SSPP) wave in microwave and terahertz ranges. In this letter, a four-way SSPP splitter/combiner with oval-ring periodic structures is presented by using a single connection junction. Up to the authors’ best knowledge, a four-way SSPP splitter/combiner is never reported in the literature. In order to verify the performance of the mentioned SSPP splitter/combiner, we have manufactured and tested the presented SSPP splitter/combiner. The simulation and measurement results demonstrate that the designed conversion between a single coplanar waveguide junction and four SSPP waveguides is high efficiency. The SSPP splitter equally separates the electromagnetic wave into four paths. Hence, the proposed four-way splitter is expected to develop the SSPP active and passive components and relative integrated circuits.
关键词： spoof surface plasmon polariton (SSPP),four-way splitter/combiner,Coplanar waveguide (CPW)
更新于2025-09-23 15:23:52
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Numerical study of nanoscale biosensor based on surface plasmon polariton propagation in Mach-Zehnder interferometer structure
摘要： In this paper, we numerically investigate a nanoscale plasmonic biosensor based on Mach-Zehnder interferometry. The operation of Mach-Zehnder interferometer (MZI) biosensor is examined based on two methods. In the first method, in which the transmission of surface plasmon polariton (SPP) modes is investigated under different refractive indices of sample medium as well as different dimensions, the best transmission rate achieved about 56.6% which is resulted by refractive index variation about 0.045 for the length 12 μm and width 80 nm of the gold layer. Also, the sensitivity, figure of merit (FOM) and quality factor (Q-factor) of MZI are examined for different geometries by utilizing the alternative method. It is realized that for the constant length, increasing the thickness of gold layer has significantly led to increased Q-factor and FOM. On the other hand, considering fixed thickness of the Au layer and three different lengths, the major outcome is that as the length of biosensor increases, the sensitivity, Q-factor as well as FOM follow an upward trend. Finally, inserting two distinct additional gold layers on top of the main gold layer, resulted in an extreme increase for the sensitivity and FOM of the plasmonic MZI biosensors with respect to the MZI biosensor without additional layer.
关键词： Plasmonic biosensor,Surface plasmon polariton (SPP),Mach-Zehnder interferometer (MZI),Finite difference time domain (FDTD)
更新于2025-09-23 15:23:52
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A compact leaky-wave antenna using a planar spoof surface plasmon polariton structure
摘要： This article presents and validates a leaky-wave antenna by using the spoof surface plasmon polariton (SSPP) technique. By properly designing the proposed SSPP unit, the SSPP wave can be switched between the confinement and radiation modes. A large radiation efficiency can be achieved by properly designing the modulation depth, which ensures that a compact SSPP leaky-wave array can be realized by using a small number of SSPP radiation units. To verify the design, a prototype which consists of a SSPP feeding network and a 4 by 4 SSPP radiation units has been fabricated by using a low cost FR-4 substrate. A good agreement between simulated and measured results has been obtained. The proposed array antenna shows the promising capability of the SSPP technique for leaky-wave antenna applications.
关键词： dispersion curve,the spoof surface plasmon polariton (SSPP),SSPP antenna array,SSPP power divider
更新于2025-09-23 15:23:52
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Polariton superregular breathers in a resonant erbium-doped fiber
摘要： We study polariton superregular (SR) breathers triggered by the resonant interaction of an optical field with two-level doping ions in an erbium-doped fiber. We demonstrate explicitly that the optical wave component always features a bright structure that describes the modulation instability (MI) development from localized small perturbations, while the SR matter-wave breathers exhibit more complicated dynamical evolution, which are absent in standard scalar SR breather theory. Despite the complexity, the exact link between these SR breathers and MI is established strictly by showing that the absolute difference of group velocities of SR breathers coincides exactly with the linear MI growth rate. In particular, we show how a small dip perturbation of the dark SR breather in the matter wave component induces an intriguing MI process of completely exponential decay. These results will enrich our understanding on the MI development in complex coupled light-matter interaction systems.
关键词： erbium-doped fiber,polariton,resonant interaction,modulation instability,superregular breathers
更新于2025-09-23 15:23:52
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[IEEE 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Waterloo, ON (2018.8.19-2018.8.22)] 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Excitation of Hyperbolic Plasmons and Transition Radiation in Phosphorene by a Swift Electron
摘要： We analyze the energy loss channels for a fast electron traversing a monolayer phosphorene under oblique incidence taking the retardation effects into account.
关键词： transition radiation,electron energy loss,retardation effects,Phosphorene,hyperbolic plasmon polariton
更新于2025-09-23 15:23:52
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[IEEE 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Waterloo, ON (2018.8.19-2018.8.22)] 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Plasmon Excitation and Transition Radiation in Graphene Traversed by a Fast Charged Particle
摘要： A progress report is presented on recent theoretical investigations of the interaction of fast charged particles with single and multiple graphene layers. By adopting a fully relativistic formulation of the problem, special focus is placed on retardation effects in the energy loss of a charged particle due to electronic excitations in graphene, which include its plasmon polariton modes, as well as the energy that is emitted from graphene in the form of transition radiation. Using both empirical and ab initio models for the dynamic in-plane conductivity of graphene allows the exploration of energy losses at frequencies ranging from the terahertz to the ultraviolet.
关键词： transition radiation,electron energy loss,graphene,relativistic effects,plasmon polariton
更新于2025-09-23 15:23:52
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Variational Solution of Steady-Structure in Exciton-Polariton Condensates with a Modified Lagrangian Approach
摘要： Exciton-polariton condensate is a new kind of system exhibiting spontaneous coherence, which is a new quantum dissipation system. Numerical simulation and analytical methods can be used to study the static and dynamical properties of exciton-polariton condensate. In this paper, A modified Lagrangian method is developed for exciton-polariton system to find the steady-state structure and regimes among the parameters of the system, and two new forms of trial wave function are proposed. The modified Lagrangian method is successfully applied to the exciton-polariton system described by the open-dissipative Gross-Pitaevskii equation for the first time. Furthermore, static version of the modified Lagrangian method provides stationary shape of the steady-state structure, while the time-dependent version can be used to study small amplitude oscillations around stationary states. On the one hand, comparison of the profiles for steady-state structure, predicted by the modified Lagrangian and those found from numerical solution of the open-dissipative Gross-Pitaevskii(dGP) equation shows good agreement, thereby proving the accuracy of the trial wave function and validating the proposed approach. Particularly, this new method promotes the deeper cognition and understanding for the dissipative exciton-polariton system and is helpful to explore the mechanism of the gain and dissipation effect on the steady-state structure of the system.
关键词： dissipative,Lagrangian method,trial wave function,exciton-polariton condensate,steady-state structure
更新于2025-09-23 15:22:29
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Dark–bright solitons in spinor polariton condensates under nonresonant pumping
摘要： By adopting a mean-field Gross-Pitaevskii description of spinor polariton Bose-Einstein condensates under nonresonant pumping, we investigate the static and dynamical properties of dark-bright (DB) solitons. We derive the equation of motion for the center of mass of the DB solitons' center analytically by using the Hamiltonian approach. The resulting equation captures how the combination of the open-dissipative character and the spin degrees of freedom of a polariton Bose-Einstein condensate affects the properties of DB solitons, i.e. DB solitons relax by blending with the background at a finite time. In this case, we also determine the lifetime of the DB solitons. Further numerical solutions of the modified dissipative two-component Gross-Pitaevskii equations are in excellent agreement with the analytical results. In the presence of the Langevin noise, we demonstrate that the DB solitons can still propagate for a long time, which is sufficient for their experimental observations within current facilities.
关键词： polariton Bose-Einstein condensate,dark-bright solitons,mean-field method,stochastic GP equations
更新于2025-09-23 15:22:29
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Strong Coupling of Magnons to Microwave Photons in Three-Dimensional Printed Resonators
摘要： We report on ferromagnetic resonant mode hybridization in re-entrant cavities made with a commercial three-dimensional (3D) printer, followed by conventional 3D metalization with copper and tin. The cavity volume was only 7% that of a standard cavity resonating at the same frequency, while maintaining a high quality factor. Simulations were in very good agreement. We obtained an effective coupling of about 40 MHz in two cavities at room temperature. These experimental results demonstrate the utility of tunable filters based on complex 3D printed cavities.
关键词： magnon photon polariton,3D Cavity spintronic,Yttrium Iron Garnet,3D printing,tunable filter
更新于2025-09-23 15:22:29