In this paper we have investigated three external fields interacting with the four-level Y-type atomic system described by the density-matrix approach. The results show that left-handedness with zero absorption is achieved. The zero absorption property displays the possibility of manipulation by varying the phase and the intensity of the coupling field. Also, the zero absorption property may be used to amplify the evanescent waves that have been lost in imaging by traditional lenses. We propose an approach to obtain a negative refractive medium with zero absorption and the possibility of enhaneeingthe imaging resolution in realizing ＇superlenses＇.
Using the first Lyapunov coefficient with precise symbolic computation,Hopf bifurcation analysis of the Lorenz...
Yang Qigui1,Liu Mengying2 1.School of Mathematical Sciences,South China University of Technology,Guangzhou 510640,P.R.China2.School of Mathematical Sciences,South China University of Technology,Guangzhou 510640,P.R.China
In the present paper, we investigate the behavior of two-dimensional atom localization in a five-level M-scheme atomic system driven by two orthogonal standing-wave fields. We find that the precision and resolution of the atom localization depends on the probe field detuning significantly. And because of the effect of the microwave field, an atom can be located at a particular position via adjusting the system parameters.
