# Unified ab initio treatment of attosecond photoionization and Compton scattering - Physics > Atomic Physics

Abstract: We present a new theoretical approach to attosecond laser-assisted photo- andCompton ionization. Attosecond x-ray absorption and scattering are described by$\hat{\mathrsfs{S}}^{1,2}$-matrices, which are coherent superpositions of-monochromatic- $\hat{S}^{1,2}$-matrices in a laser-modified Furryrepresentation. Besides refining the existing theory of the soft x-rayphotoelectron attosecond streak camera and spectral phase interferometry ASCand ASPI, we formulate a theory of hard x-ray photoelectron and Compton ASCand ASPI. The resulting scheme has a simple structure and leads to closed-formexpressions for ionization amplitudes. We investigate Compton electroninterference in the separable Coulomb-Volkov continuum with both Coulomb andlaser fields treated non-perturbatively. We find that at laser-fieldintensities below 10$^{13}$ Wcm$^{-2}$ normalized Compton lines almost coincidewith the lines obtained in the laser-free regime. At higher intensities,attosecond interferences survive integration over electron momenta, and featureprominently in the Compton lines themselves. We define a regime where theelectron ground-state density can be measured with controllable accuracy in anattosecond time interval. The new theory provides a firm basis for extractingphoto- and Compton electron phases and atomic and molecular wavefunctions fromexperimental data.

Author: G. L. Yudin, D. I. Bondar, S. Patchkovskii, P. B. Corkum, A. D. Bandrauk

Source: https://arxiv.org/