Fig. 1. (a) CMD of correlated electron pairs at final state and (b) momentum distribution of Mg2+ when laser power density is 1×1013 W·cm-2; CMDs along (c) x and (d) y directions of correlated electron pairs at final state when laser power density is 3×1013 W·cm-2

Fig. 2. (a) NSDI trajectory counts versus delay time; CMDs of two electrons along x direction for(b) Δt<0.5T and (c) Δt>0.5T

Fig. 3. Recollision events (green region) and double ionization events (red region) versus delay time when (a) Δt<0.5T and (b) Δt>0.5T

Fig. 4. Correlated-electron energy distributions under (a) 1.14T, (b) 1.34T, (c) 1.16T and (d) 1.66T

Fig. 5. (a)(c) Energy and (b)(d) momentum trajectories of electrons

Fig. 6. (a) CMD along x direction in NSDI for Δt<0.5T when laser power density is 1×1013 W·cm-2; (b) recollision events (green region) and double ionization events (red region) versus time; CMDs along x direction in NSDI for (c) Δt<0.5T and (d) Δt>0.5T when laser power density is 2×1013 W·cm-2