Fig. 1. CMDs of NSDI for Ar atoms in linearly polarized four-cycle laser pulses with laser wavelength of 750 nm and laser intensity of 3 × 1014  W/cm2. The CEP φ is (a) all CEPs averaged, (b) −π/3, (c) π/4, and (d) 5π/6, respectively.

Fig. 2. Recollision trajectories counts versus time for different CEPs from Figs. 1(b)–1(d). The blue curves represent the laser field along the x axis.

Fig. 3. CMDs in NSDI of Ar atoms by 750 nm linearly polarized two-cycle laser pulses with laser intensity at 3 × 1014  W/cm2. The CEP φ is chosen as (a) 0, (b) π/4, (c) π/2, and (d) 5π/6, respectively.

Fig. 4. (a) SI and (e) RC events [from Fig. 3(a)] versus time, (b) SI and (f) RC events [from Fig. 3(b)] versus time, (c) SI and (g) RC events [from Fig. 3(c)] versus time, (d) SI and (h) RC events from Fig. 3(d) versus time. The blue curves represent the laser field along the x direction.

Fig. 5. CMDs of Ar atoms by linearly polarized two-cycle laser pulses at RC times (a) less than 1.15T, (b) greater than 1.15T for the CEP of φ= 0, and (c) less than 1.4T, (d) greater than 1.4T for the CEP of φ= π/2. The other parameters are the same as those in Fig. 3.

Fig. 6. (a) and (b) Two typical energy trajectories with CEP φ= π/2, and (c) and (d) corresponding momentum trajectories along the x direction. Black dashed lines denote the electric field of the laser pulses, blue and red curves denote the evolutions of the two electrons, and the other parameters are the same as those in Fig. 3(c).

Fig. 7. Distributions of ΔE (the absolute value of the energy difference between the two electrons) at RC times (a) 1.3T and (b) 1.5T with CEP of φ= π/2, respectively. (c) and (d) are the corresponding transverse momentum spectra of the two electrons at two RC times. The other parameters are the same as those in Fig. 3.