Dependence of photoelectron-momentum distribution of H₂⁺ molecule on orientation angle and laser ellipticity

By numerically solving the two-dimensional time-dependent Schrödinger equation under the frozen-nuclei approximation, we are able to study the molecular photoelectron-momentum distribution (MPMD) of H₂⁺ with different orientation angles driven by elliptically polarized laser pulse with varying ellipticities. Our numerical results show that the MPMD is sensitive to the orientation angle and the laser ellipticity, which can be explained by the attosecond perturbation ionization theory and the exactly solvable photoionization model. When the ellipticity ε=0, the final MPMD of x-oriented H₂⁺ shows a distinct six-lobe pattern that is different from that with ε=0.5 and ε=1. The evolutions of electron wave packet (EWP) and MPMD with x-oriented H₂⁺ are presented to interpret this distinct pattern.