Imaging charge migration in the asymmetric molecule with the holographic interference in strong-field tunneling ionization

Abstract

Coherent superposition of several electronic states in molecules induces attosecond charge migration. We theoretically demonstrate a way to observe this attosecond charge migration in the asymmetric molecule HeH2+ using strong-field photoelectron holography, complementary to our previous work (He M et al 2018 Phys. Rev. Lett. 120, 133204) where the charge migration in the symmetric molecule was monitored. We disentangle the holographic interference from other types of interference in the photoelectron momentum distribution with the Fourier frequency filter method. By employing the holographic fringes originating from the ground state of HeH2+ as a reference, we develop a feasible approach to visualize the charge migration in the asymmetric molecule with attosecond temporal resolution.