An understanding of the role of the atomic and molecular structures in harmonic spectra and above-threshold photoelectron spectra is expected to help in the tomographic reconstruction of the atomic and molecular states. The evidence to support multielectron interpretation would seem inconclusive.

Researchers at Shanghai Institute of Optics and Fines Mechanics (SIOM/China)——State Key Laboratory for High-Field Laser Physics theoretical study shows that the spectral minimum and the giant enhancement structures observed in the high harmonic spectra also exist in the photoelectron spectra from driven Xe atoms. [Physical Review Letters,110, 063002 (2013)]They are attributed to the inherent property of the radial part of the wave function of the Xe 5p subshell in momentum space. The spectral minimum is caused by the nodal point in the modulus of the radial wave function in momentum space, and the giant enhancement reflects the increase in magnitude of the modulus of the wave function. To observe these structures, midinfrared lasers of about 0.2 PW/cm2 intensity are preferred. Employing circularly polarized laser light is suggested for exhibiting these structures in photoelectron spectra.