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Title: The terahertz dynamics of simplest fluids probed by inelastic X-ray scattering

More than two decades of inelastic X-ray scattering (IXS) studies on noble gases and alkali metals are reviewed to illustrate the advances they prompted in our understanding of the terahertz dynamics of simplest systems. The various literature results outline a remarkably coherent picture of common and distinctive behaviours of liquids and their crystalline counterparts. Furthermore, they draw a consistent and comprehensive picture of the evolution of collective modes at the crossover between the hydrodynamic and the single particle regime, their coupling with fast (sub-ps) relaxation processes and their gradual disappearance upon approaching microscopic scales. The gradual transition of the spectrum towards the single particle limit along with its coupling with collisional relaxations will be discussed in some detail. Lastly, less understood emerging topics will be discussed as the occurrence of polyamorphic crossovers, the onset of non-hydrodynamic modes and quantum effects on the spectrum, as well as recent IXS results challenging our vision of the supercritical phase as an intrinsically homogeneous thermodynamic domain.
  1. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 0144-235X
Grant/Contract Number:
Accepted Manuscript
Journal Name:
International Reviews in Physical Chemistry
Additional Journal Information:
Journal Volume: 36; Journal Issue: 3; Journal ID: ISSN 0144-235X
Taylor & Francis
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; Inelastic X-ray Scattering; Inelastic Neutron Scattering; Noble Gases; Relaxation Phenomena; Liquid and Supercritical Systems
OSTI Identifier: