Fig. 1. Schematic of theoretical model. (a) Propagation schematic of probe field, control field, and adscititious non-resonance Stark field in Λ type three energy-level atomic gas; (b) energy-level diagram and excitation scheme of Λ type three energy-level atomic gas

Fig. 2. Propagation modes of soliton excited in the barrier. (a) Excitation process of single soliton incidence; (b) excitation process of double solitons symmetric incidence

Fig. 3. Propagation modes of soliton excited in the barrier in case of asymmetric incidence. (a) V0=6.2,β=4; (b) V0=7.5,β=4

Fig. 4. Influence of barrier intensity to excited modes. (a) Average intensity u2¯ of excited modes as a function of barrier intensity V0;(b) corresponding waveshapes of excited modes under different barrier intensities

Fig. 5. Influence of barrier width to excited modes. (a) Average intensity u2¯ of excited modes as a function of β;(b) corresponding waveshapes of excited modes under different barrier widths

Fig. 6. Excitation of double solitons with different phase differences in barrier. (a) Δφ=0; (b) Δφ=π; (c) Δφ=π/4; (d) Δφ=π/2;(e) Δφ=4π/3; (f) u2¯ as a function of Δφ