Three-dimensionally isotropic negative refractive index assisted by two-photon resonance via quantum coherence

摘要

An experimentally feasible and promising scheme for realizing simultaneously negative permittivity and permeability in a single-photon off-resonant atomic vapor is suggested by taking full advantage of the mechanism of two-photon resonance that is assisted by atomic phase coherence. The present quantum-coherent atomic vapor can exhibit three-dimensionally isotropic negative refractive index (NRI) at visible and near-infrared wavelengths, and would find potential applications in design of NRI-based quantum optical and photonic devices.