Nonreciprocal negative refraction in a dense hot atomic medium

We investigate the electromagnetic properties of a four-level dense atomic gas medium with Doppler effect. It is shown that the relative permittivity and relative permeability of the medium can be negative simultaneously with low absorption in the same detuning interval on account of electromagnetically induced transparency. Furthermore, with the suitable parameters, the nonreciprocal negative refraction can be obtained due to the Doppler effect, and the nonreciprocity frequency band can be regulated by adjusting the temperature, the intensity of the control field and the atomic density in this hot atomic medium.

Automated summary

We study the electromagnetic properties of a dense atomic gas medium with Doppler effect on four energy levels. The results show that due to the electromagnetically induced transparency, the relative permittivity and permeability of the medium can be simultaneously negative with low absorption in the same detuning interval. Moreover, by adjusting the temperature, control field intensity, and atomic density, the nonreciprocal negative refraction resulting from the Doppler effect can be achieved, and the nonreciprocity frequency band can be regulated.