The onset of shear modes in the high frequency spectrum of simple disordered systems: current knowledge and perspectives

Abstract

Nearly two decades of thorough inelastic X-ray scattering (IXS) studies of transverse-like excitation in the spectrum of simple amorphous materials are reviewed. Particular attention is given to the case of liquid water and other prototypical samples, through discussion of both solved and still open issues. The perspectives opened up by the development of next generation IXS instruments with unprecedented contrast and resolution bandwidth are briefly illustrated.

Keywords:

• inelastic X ray scattering
• non-hydrodynamic modes
• disordered systems

Acknowledgements

Work performed at the National Synchrotron Light Source II, Brookhaven National Laboratory, was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012704.

Disclosure statement

No potential conflict of interest was reported by the authors.