标题： 左 handed 四级原子介质中的零吸收和大负折射率 显示英文标题

标题： Zero absorption and large negative refractive index in a left-handed four-level atomic media

摘要： 本文研究了三种外场与由密度矩阵方法描述的四能级原子系统的相互作用。该原子系统表现出左手性，具有零吸收和大负折射率的特性。通过改变三个外场的参数，原子系统的零吸收和大负折射率特性保持不变。本方案提出了一种获得零吸收负折射介质的方法。 原子系统的零吸收特性可用于放大传统透镜成像过程中损失的倏逝波。而由左手性原子系统制成的薄板可能是设计完美透镜的理想候选材料。 显示英文摘要

摘要： In this paper,we have investigated three external fields interacting with the four-level atomic system described by the density-matrix approach.The atomic system exhibits left-handedness with zero absorption as well as large negative refractive index.Varying the parameters of the three external fields,the properties of zero absorption,large negative refractive index from the atomic system keep unvarying.Our scheme proposes an approach to obtain negative refractive medium with zero absorption. The zero absorption property of atomic system may be used to amplify the evanescent waves that have been lost in the imaging by traditional lenses.And a slab fabricated by the left-handed atomic system may be an ideal candidate for designing perfect lenses.