Photoelectron momentum distributions at 996 nm, with the laser parameters the same as those in Fig. 1, calculated for Yukawa potentials with different parameters: (a) κ = 0.45, (b) κ = 0.3, (c) κ = 0.15, (d) κ = 0.1, (e) κ = 0.05, (f) κ = 0.02. The number of bound states from panels (a) to (f) is 1, 2, 2, 3, 4, and 5 respectively. For better visibility, different color bars are used for the first and the second rows.