Negative refraction with absorption suppressed by electromagnetically induced transparency in a left-handed atomic system

This paper intends to realize negative refraction with absorption suppressed by the electromagnetically induced transparency （EIT） in a dense four-level atomic system. Without the two equal transition frequencies responding to the probe field, the atomic system displays a negative refraction with the simultaneously negative permittivity and negative permeability （left-handedness）. The response of the probe field is amplified and propagates transparency in some frequency extents. Therefore, our aim for searching the low-loss negative refraction can be achieved in the scheme, given the main applied limitation of the negative refractive materials is the large amount of dissipation and absorption. However, an excessive signal field intensity would increase the absorption near the resonance in our scheme.