Precise control of the recollision dynamics in nonsequential double ionization by spatially inhomogeneous few-cycle negatively chirped laser pulses

With a three-dimensional semiclassical ensemble method, we theoretically investigated the nonsequential double ionization (NSDI) of Ar driven by the spatially inhomogeneous few-cycle negatively chirped laser pulses. Our results show that the recollision time window can be precisely controlled within an isolated time interval of several hundred attoseconds, which is useful for understanding the subcycle correlated electron dynamics. More interestingly, the correlated electron momentum distribution (CEMD) exhibits a strong dependence on laser intensity. That is, at lower laser intensity, the correlated electron momentum distribution is located in the first quadrant. As the laser intensity increases, the correlated electron momentum distribution shifts almost completely to the second and fourth quadrants, and then gradually to the third quadrant. The underlying physics governing the CEMD’s dependence on laser intensity is explained.