Interference structures of an Ar atom by orthogonally polarized laser pulses

Tunneling ionization is one of the basic physical processes in strong-field physics. Photoelectron holographic (PH) interference in tunneling ionization has become one of the research hotspots in strong-field physics. We investigate the interference structure of an Ar atom in orthogonally polarized laser pulses by the quantum-trajectory Monte Carlo (QTMC) model. The results show the ``inner spider'' holographic interference structure and above-threshold ionization (ATI) ring interference structure in photoelectron momentum distributions (PMDs) of the Ar atom at $\mathrm{\ensuremath{\Delta}}t=0$. However, as the time delay increases, the interference structure gradually becomes distorted until it is completely destroyed. We find that the interference structure at the PMDs center can only be identified clearly when the time delay has three or fewer optical periods, which indicates that the stability and observability of the interference structure are closely related to the number of periods of the selected time delay. By tracing the trajectories of ionized electrons, we find that the quadrant of the final position of the ionized electron trajectory is consistent with the quadrant of the PMDs for this time window. Furthermore, we find that the inner spider structure disappears when the Coulomb potential is ignored, which is due to the Coulomb focusing effect by analyzing the emission angle of the ionized electrons.