Abstract. Negative refractive index is introduced in metamaterials whereby the Poynting vector of the electromagnetic (EM) wave is in opposition to the group velocity, or alternatively, when the group and phase velocities in the medium are in opposition. In recent years, considerable research has been carried out relative to the EM propagation and refraction characteristics in metamaterials with emphasis on the origins of negative refractive index. The latter phenomenon has been extensively investigated in the literature, including recent work involving chiral metamaterials with material dispersion up to the first and second orders. An EM propagation in a chiral, dispersive material up to the first order is examined for possible emergence of negative refractive index under non-conductive losses. Three loss scenarios are considered, viz., dielectric losses (complex permittivity), magnetic losses (complex permeability), and a combination of both types of losses. A spectral approach combined with a slowly time-varying phasor analysis is applied, leading to the analytic derivation of EM phase and group velocities and corresponding indices. The velocities and indices are examined by selecting arbitrary dispersion parameters based on published practical values. The results indicate the emergence of negative index within specific radio frequency modulation bands. The resulting polarization states of the fields are examined under loss conditions. Finally, a method is suggested whereby the effects of dielectric and magnetic losses may be combined via appropriate Taylor coefficients such that the effective attenuation constant may be driven to zero via induced gain mechanisms arising from the dielectric and magnetic loss models.

中文翻译：

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损耗对手性电介质中负指数行为的影响以及介电损耗和磁损耗之间的折衷，以实现零有效衰减

摘要。在超材料中引入负折射率，由此电磁 (EM) 波的坡印廷矢量与群速度相反，或者当介质中的群速度和相速度相反时。近年来，已经对超材料中的电磁传播和折射特性进行了大量研究，重点是负折射率的起源。后一种现象已在文献中进行了广泛的研究，包括最近涉及材料色散达到一阶和二阶的手性超材料的工作。检查了在手性色散材料中达到一阶的 EM 传播，以确定在非导电损耗下可能出现的负折射率。考虑了三种损失情况，即，介电损耗（复介电常数）、磁损耗（复磁导率）以及这两种损耗的组合。应用谱方法与缓慢时变相量分析相结合，导致对 EM 相位和群速度以及相应指数的分析推导。通过基于已发布的实用值选择任意分散参数来检查速度和指数。结果表明在特定射频调制频带内出现了负指数。在损耗条件下检查产生的场极化状态。最后，