Laser-induced nonsequential double ionization in diatomic molecules: one and two-center rescattering scenarios

We investigate laser-induced nonsequential double ionization from aligned diatomic molecules, using the strong-field approximation in its length and velocity gauge formulations. Throughout, we consider that the first electron dislodges the second by electron-impact ionization. Employing modified saddlepoint equations, we single out the contributions of different scattering scenarios to the maxima and minima observed in the differential electron momentum distributions. We show that the main contributions to such patterns is caused by the quantum interference between the electron orbits starting and ending at a specific center Cj , and those starting at Cj and ending at a different center Cν . Indeed, the distributions obtained considering only such processes are practically identical to those obtained using all possible scenarios. In contrast, the interference between topologically similar scenarios leads at most to patterns whose positions, in momentum space, do not agree with the overall interference condition. These conclusions hold both in the length and in the velocity gauge. PACS numbers: 32.80.Rm, 33.80.Rv