Interpreting the Terahertz Spectrum of Complex Materials: The Unique Contribution of the Bayesian Analysis

Materials

Alessandro Cunsolo¹  Ferdinando Formisano²  Alessio De Francesco²  Ubaldo Bafile³  Luisa Scaccia⁴  Eleonora Guarini⁵  Marco Maccarini⁶ 

[1] Brookhaven National Laboratory-National Synchrotron Light Source-NSLS II, P.O. Box 5000, Upton, NY 11973, USA;Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali, Operative Group in Grenoble (OGG), c/o Institut Laue Langevin, 38042 Grenoble, France;Consiglio Nazionale delle Ricerche, Istituto di Fisica Applicata “Nello Carrara”, via Madonna del Piano 10, I-50019 Sesto Fiorentino, Italy;Dipartimento di Economia e Diritto, Università di Macerata, Via Crescimbeni 20, 62100 Macerata, Italy;Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino, Italy;Laboratoire TIMC/IMAG UMR CNRS 5525 Grenoble, Université Grenoble-Alpes, 38000 Grenoble, France;

关键词: terahertz spectroscopy;    Bayesian analysis;    model choice;    liquids dynamics;    inelastic neutron scattering;    inelastic X-ray scattering;   

DOI  :  10.3390/ma12182914

来源: DOAJ

【 摘 要 】

In the last few decades, experimental studies of the terahertz spectrum of density fluctuations have considerably improved our knowledge of the mesoscopic dynamics of disordered materials, which also have imposed new demands on the data modelling and interpretation. Indeed, lineshape analyses are no longer limited to the phenomenological observation of inelastic features, as in the pioneering stage of Neutron or X-ray spectroscopy, rather aiming at the extraction from their shape of physically relevant quantities, as sound velocity and damping, relaxation times, or other transport coefficients. In this effort, researchers need to face both inherent and practical obstacles, respectively stemming from the highly damped nature of terahertz modes and the limited energy resolution, accessible kinematic region and statistical accuracy of the typical experimental outcome. To properly address these challenges, a global reconsideration of the lineshape modelling and the enforcement of evidence-based probabilistic inference is becoming crucial. Particularly compelling is the possibility of implementing Bayesian inference methods, which we illustrated here through an in-depth discussion of some results recently obtained in the analysis of Neutron and X-ray scattering results.

【 授权许可】

Unknown