Photoionization of triatomic molecular ions ${{\rm{H}}}_{3}^{2+}$ by intense bichromatic circularly polarized attosecond UV laser pulses

Abstract

Photoionization of triatomic molecular ions has been studied for triangular and linear geometries by bichromatic circularly polarized attosecond UV laser pulses at frequencies . Simulations are performed on the single electron molecule by numerically solving time-dependent Schrödinger equations. We measure molecular frame photoelectron momentum distributions (MFPMDs), which show spiral electron vortex patterns as functions of the helicity of the pulse and the molecular geometry. The ionization interference effects arise from multi-pathway ionization, which give rise to the modulation of multi-center photoelectron spectra. We describe these phenomena in MFPMDs based on an ultrafast delta-function ionization model and attosecond perturbation ionization theory. Interference patterns in MFPMDs reflect the helicity and symmetry of the electric fields in the attosecond ionizing pulses.