We report the progress in our research on the quantum coherence in multi-level atomic gases, especially the double electromagnetically induced transparency effect in four-level N-type and tripod-type atomic medium.
The electromagnetically induced transparency (EIT) phenomenon in a four level atomic system with tripod configuration is studied. The results show that this configuration is equivalent to the combination of two single three-level Λ configurations, which, under certain conditions, results in the so-called double-EIT (DEIT) phenomenon. The properties of the double transparency windows for DEIT are discussed in detail and the possible experimental scheme is proposed.
Summary form only given. Quantum coherence effects in atomic media interacting with multiple coherent electromagnetic fields have gained a lot of attention in both theoretical and experimental quantum optics over the last three decades. The absorptive and dispersive properties of coherently prepared media lead. Astonishing effects like electromagnetically induced transparency on extremely narrow dark resonances and recently the reduction of pulse propagation velocities down to Volkswagen speed have been observed.