Laser pulses for coherent xuv Raman excitation.

Abstract

We combine multi-channel electronic structure theory with quantum optimal control to 
derive Raman pulse sequences that coherently populate a valence excited state. For a 
neon atom, Raman target populations of up to 13 percent are obtained. Superpositions of the ground and valence Raman states with a controllable relative phase are found to
be reachable with up to 4.5 percent population and phase control facilitated by the 
pump pulse carrier envelope phase. Our results open a route to creating core-hole 
excitations in molecules and aggregates that locally address specific atoms and 
represent the first step towards realization of multidimensional spectroscopy in the 
xuv and x-ray regimes.