Nonresonant coherent amplitude transfer in attosecond four-wave-mixing spectroscopy

Abstract

The authors use attosecond four-wave-mixing spectroscopy to measure coherent superpositions of Rydberg states resulting from extreme ultraviolet excitation of a 3$s$ electron in gas phase atomic argon to a series of autoionizing 3$s$-1$n\phantom{\rule{0}{0ex}}p$ Rydberg states. The experimental observations are reproduced by electronic-structure and transition-moment calculations.