Circularly polarized RABBITT on atomic shells with large orbital momentum

In light atoms, the technique of Reconstruction of Attosecond Bursts by Interference of Two-Photon Transitions (RABBITT), driven by circularly polarized radiation, enables a complete retrieval of ionization amplitudes in the XUV+IR regime, including their relative phases (Kheifets 2024 Phys. Rev. Res. 6 L012002). In this work, we extend this method to heavier atoms by conducting numerical simulations of circularly polarized RABBITT on the Kr 3d and Xe 4d atomic shells. The XUV ionization dynamics in these atoms differ markedly due to the presence of a ‘giant’ shape resonance in the 4 d → E f ionization channel of Xe, a feature absent in Kr. Nevertheless, when an IR photon is added to the XUV ionization, the results for Kr and Xe are surprisingly similar, with the ratio of absorption/emission matrix elements and their relative phases remaining close in value. Moreover, these ratios and phases show minimal variation even when the Xe atom is encapsulated within a C₆₀ fullerene cage. In search for the Cooper-like minimum in the IR absorption amplitude ratios predicted in Ji et al (2024 J. Phys. B 57 235601), we extend our investigation to the Ce 4f shell where this minimum is indeed present.