Observation of strong nonlinear interactions in parametric down-conversion of x-rays into ultraviolet radiation
arXiv:1904.13146 · doi:10.1038/s41467-019-13629-w
Abstract
Nonlinear interactions between x-rays and long wavelengths can be used as a powerful atomic scale probe for light-matter interactions and for properties of valence electrons. This probe can provide novel microscopic information in solids that existing methods cannot reveal, hence to advance the understanding of many phenomena in condensed matter physics. However, thus far, reported x-ray nonlinear effects were very small and their observations required tremendous efforts. Here we report the observation of unexpected strong nonlinearities in parametric down-conversion (PDC) of x-rays to long wavelengths in gallium arsenide (GaAs) and in lithium niobate (LiNbO3) crystals, with efficiencies that are about 4 orders of magnitude stronger than the efficiencies measured in any material studied before. These strong nonlinearities cannot be explained by any known theory and indicate on possibilities for the development of a new spectroscopy method that is orbital and band selective. In this work we demonstrate the ability to use PDC of x-rays to investigate the spectral response of materials in a very broad range of wavelengths from the infrared regime to the soft x-ray regime.
arXiv comment31 pages, 10 figures
References in corpus (5)
- Resonant Inelastic X-ray Scattering Studies of Elementary Excitations
- Coherent ultrafast core-hole correlation spectroscopy: x-ray analogues of multidimensional NMR
- X-Ray sum frequency generation; direct imaging of ultrafast electron dynamics
- Explaining the x-ray nonlinear susceptibility of diamond and silicon near absorption edges
- Theory of nonlinear interactions between x rays and optical radiation in crystals