Two-center interference in high-harmonic generation of H_2~+ in a combination of a mid-infrared laser field and a terahertz field

We theoretically investigate the two-center interference in high-order harmonics generated from the H₂⁺ in a combination of a mid-infrared laser and a terahertz field by numerically solving the time-dependent Schrödinger equation (TDSE). The interference minima in high-order harmonic generation (HHG) are effectively suppressed when a THz field is added. The contribution to HHG from the two separate nuclei is used to demonstrate the locating order of the harmonic minima. Furthermore, we also investigate the emission time of harmonics. The results show that the intensity of the short path around 60^th order after adding a THz field is stronger than that in the mid-infrared laser field, which further illustrates the suppression of the interference minima in HHG.