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在金属板与电介质材料板基底间插入色散特异材料板形成三明治结构,并对其Casimir作用力进行了研究.基于Casimir-Lifshitz理论,通过麦克斯韦应力张量计算了真空涨落的辐射压,并对三明治结构利用电磁模式传输矩阵方法进行了数值计算分析.计算结果表明,原本两板结构中存在的Casimir吸引力,在插入特异材料板后的三明治结构中将转变为斥力,从而使轻薄的金属板产生量子悬浮效应。讨论了特异材料板的色散电磁响应特性以及电介质板基底的影响,结果表明特异材料磁等离子频率越大、磁共振频率越小以及电介质板基底的介电常数越小时,三明治结构中获得的斥力越大.此外,板间距增加到一定范围时,三明治结构中将出现Casimir平衡回复力.特异材料填充因子越小、三明治结构中层距和层厚越大时,三明治结构间的回复力会出现在较长距的位置.三明治结构中的量子悬浮效应与平衡回复力可保证微纳米机械系统稳定性,展现出基于真空辐射压的应用前景. 相似文献
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Random resonant media being one of the possible realizations of disordered metamaterials open a room of opportunities for achieving new fundamental effects and designing advanced nanophotonic devices. Strongly nonlinear optical properties of such media attract ever increasing attention nowadays from both theoretical and experimental points of view. Hereinafter, the case of the photonic‐crystal‐like structure with a randomly varying light–matter coupling provided by the random density of quantum particles is considered. Using numerical solution of the Maxwell–Bloch equations, the effects of the pulse collisions in the medium are studied. It is shown that disorder enables the qualitative changes of the system's response for co‐propagating pulses, whereas this is not the case for the counter‐propagating ones. The scheme for an all‐optical transmission modulation due to the disorder‐induced inelasticity of collisions of co‐propagating pulses is proposed. The ability of precise tuning the modulation via the inter‐pulse distance and background refractive index adjustment is revealed. This novel approach for light control can be utilized for some high demand applications, such as modulation and switching of a pulsed radiation. 相似文献
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Quantum Transport in the Black‐Hole Configuration of an Atom Condensate Outcoupled Through an Optical Lattice 下载免费PDF全文
The outcoupling of a Bose‐Einstein condensate through an optical lattice provides an interesting scenario to study quantum transport phenomena or the analog Hawking effect as the system can reach a quasi‐stationary black‐hole configuration. We devote this work to characterize the quantum transport properties of quasi‐particles on top of this black‐hole configuration by computing the corresponding scattering matrix. We find that most of the features can be understood in terms of the usual Schrödinger scattering. In particular, a transmission band appears in the spectrum, with the normal‐normal transmission dominating over the anomalous‐normal one. We show that this picture still holds in a realistic experimental situation where the actual Gaussian envelope of the optical lattice is considered. A peaked resonant structure is displayed near the upper end of the transmission band, which suggests that the proposed setup is a good candidate to provide a clear signal of spontaneous Hawking radiation. 相似文献
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An electromagnetically induced transparency metamaterial (EITM) based on dielectric resonators is presented in this paper, which consists of a cut wire (CW) and ten dielectric columns. Destructive interference between the CW, which is a branch of the microstrip line, and the dielectric resonators causes the EIT phenomenon. The simulation results show that the dielectric-based EITM designed can obtain a transmission peak of 0.938 at 2.17 GHz, and the two-oscillator model is utilized to verify the effectiveness of the structure. In addition, samples of the dielectric-based EITM are also fabricated and the effectiveness of the metamaterial is experimentally verified. The proposed metamaterial has several advantages, including high efficiency, low loss, a simple structure, and ease of manufacture, which has good prospects for application in the fields of electromagnetic switches, sensors, and nonlinear metamaterials. 相似文献
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Quantum chromodynamics corrections to orderα
s (the running coupling constant), using the quark-parton approach are calculated for the spin-dependent structure functions
in deep-inelastic polarised electron-nucleon scattering. Consequences of these corrections for the Bjorken sum rule and the
asymmetry in the case of longitudinally polarised (with respect to the beam) nucleons is discussed which could provide possible
tests of quantum chromodynamics. Comparison of our results with the moments of the flavour non-singlet contribution to the
structure functions obtained using operator product expansion is also given.
An erratum to this article is available at . 相似文献
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Out‐of‐Equilibrium Fluctuation‐Dissipation Relations Verified by the Electrical and Thermoelectrical AC‐Conductances in a Quantum Dot 下载免费PDF全文
Adeline Crépieux 《Annalen der Physik》2017,529(9)
The electrical and heat currents flowing through a quantum dot are calculated in the presence of a time‐modulated gate voltage with the help of the out‐of‐equilibrium Green function technique. From the first harmonics of the currents, we extract the electrical and thermoelectrical trans‐admittances and ac‐conductances. Next, by a careful comparison of the ac‐conductances with the finite‐frequency electrical and mixed electrical‐heat noises, we establish the fluctuation‐dissipation relations linking these quantities, which are thus generalized out‐of‐equilibrium for a quantum system. It is shown that the electrical ac‐conductance associated to the displacement current is directly linked to the electrical noise summed over reservoirs, whereas the relation between the thermoelectrical ac‐conductance and the mixed noise contains an additional term proportional to the energy step that the electrons must overcome when traveling through the junction. A numerical study reveals however that a fluctuation‐dissipation relation involving a single reservoir applies for both electrical and thermoelectrical ac‐conductances when the frequency dominates over the other characteristic energies. 相似文献
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In this paper we generalize the quantization procedure of Toda–mKdV hierarchies to the case of arbitrary affine (super)algebras. The quantum analogue of the monodromy matrix, related to the universal R-matrix with the lower Borel subalgebra represented by the corresponding vertex operators is introduced. The auxiliary L-operators satisfying RTT-relation are constructed and the quantum integrability condition is obtained. General approach is illustrated by means of two important examples. 相似文献
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柱形量子点中的三阶极化率 总被引:5,自引:5,他引:0
利用量子力学的密度矩阵理论,在有效质量近似下,采用有限深势阱模型,导出了柱形量子点的三阶非线性极化率的解析表达式.通过数值计算,分析了GaAs/AlβGa1-βAs柱形量子点的三阶非线性极化率与量子点尺寸、掺杂浓度、入射光的频率和偏振方向等参量的关系.结果表明,三阶极化率峰值位置与这些参量密切相关,并且对于确定频率和偏振方向的入射光以及材料的掺杂浓度,存在与之相匹配的量子点尺寸,使三阶极化率达到极大,比体材料的相应值高出2个数量级以上. 相似文献
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A gauge-invariant Green’s function approach to the quantum transport of spatially confined electrons in strong electromagnetic fields is presented. The theory includes mean field and exchange effects, as well as collisions and initial correlations. It allows for a self-consistent treatment of spectral properties and collective effects (plasmons), on one hand, and nonlinear field phenomena, such as harmonic generation and multiphoton absorption, on the other. It is equally applicable to electrons in quantum dots, ultracold ions in traps and valence electrons of metal clusters. 相似文献
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应用多光子非线性Compton散射模型和时域有限差分法,对多光子非线性Compton散射对非均匀等离子体光子晶体光子带隙特性的影响进行了研究,提出将入射和散射光作为形成光子带隙的新机制,对电磁波方程进行了修正.结果表明:与Compton散射前相比,散射使电磁波幅值衰减更快|随等离子体密度增加,透射谱禁带宽度几乎无变化,其中心频率向高频方向有明显移动,向上的峰值有较大增加,反射谱向下的峰值有明显减小|随温度增加,透射谱禁带宽明显减小,向上的峰值略有减小,透射能量有所降低|随两种介质介电系数比增加,光子禁带数增加,且带隙间距显著减小. 相似文献
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We study the possible advantages of adopting quantum strategies in multi-player evolutionary games. We base our study on the three-player Prisoner’s Dilemma (PD) game. In order to model the simultaneous interaction between three agents we use hypergraphs and hypergraph networks. In particular, we study two types of networks: a random network and a SF-like network. The obtained results show that in the case of a three-player game on a hypergraph network, quantum strategies are not necessarily stochastically stable strategies. In some cases, the defection strategy can be as good as a quantum one. 相似文献
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Quantum Kinetic Theory of a Massless Scalar Model in the Presence of a Schwarzschild Black Hole 下载免费PDF全文
Slava Emelyanov 《Annalen der Physik》2017,529(10)
We employ quantum kinetic theory to investigate local quantum physics in the background of spherically symmetric and neutral black holes formed through the gravitational collapse. For this purpose in mind, we derive and study the covariant Wigner distribution function near to and far away from the black‐hole horizon. We find that the local density of the particle number is negative in the near‐horizon region, while the entropy density is imaginary. These pose a question whether kinetic theory is applicable in the near‐horizon region. We elaborate on that and propose a possible interpretation of how this result might nevertheless be self‐consistently understood. 相似文献