The sample points in momentum distribution and the corresponding M p ( α ) in the complex plane. In panels (a) and (c), the selected sample points around the interference fringes are shown in the zoom view of momentum distribution as presented in Figs. 2(b) (counter-rotating) and 2(a) (co-rotating), respectively, for counter-rotating and co-rotating fields. The averaged complex-valued M p ( α ) of trajectories, whose asymptotic momenta are within the bin indicated by points in panels (a) and (c), are presented in panels (b) and (d), respectively. The dominant types of trajectories are distinguished by different colors.