Light drag in an optically dense left-handed atomic medium

Abstract

In this paper, we investigate the light drag in an optically dense negative refractive index medium. Our model is a four-level atomic system in which we demonstrate an enhancement of the light drag while keeping the negative refraction condition. Furthermore, we control the shift in the light-drag by tuning both the strong coupling field and the detuning. Hence, we observe that, the light drag in the negative refractive index material can be controlled to switch from subluminal to superluminal at various range of the detuning. Our system suggests a straight forward technique for realizing and controlling light dragging in materials with negative refractive indices, or "NRI," which might open the way for more efficient use of left-handedness in atomic systems.