Localized Core Four-Wave Mixing Buildup in the X-ray Spectrum of Chemical Species

Using the Kohn-Sham density functional theory, we numerically study the four-wave mixing response of a carbon atom model system exposed to a train of femtosecond two color omega-3 omega random phase coherent X-ray pulses near the K-edge. The phase-sensitivity cancellation of the 5 omega anti-Stokes component previously described in two- and three-level systems in the infrared and optical regions is extended into the X-ray. Resonances with the absorption lines in the XANES and EXAFS regions produce 5w peak intensities that increase near the phase-sensitivity cancellation frequencies. Based on this effect, we predict that highly selective intense X-ray 5 omega photon energies can be achieved in real systems. The high localization of the omega-3 omega four-wave mixing nonlinear technique that we address entails a new valuable tool in X-ray spectroscopies of chemical species as it can readily be extended to different photon energies in other atomic absorption edges, with broad applications.

Automated summary

Using the Kohn-Sham density functional theory, the numerical study of the four-wave mixing response of a carbon atom model system near the K-edge under X-ray pulses reveals the phase-sensitivity cancellation of the 5 omega anti-Stokes component as well as the potential for achieving highly selective intense X-ray 5 omega photon energies. This localization of the four-wave mixing nonlinear technique can be extended to different photon energies in other atomic absorption edges, offering valuable applications in X-ray spectroscopies of chemical species.