Role of the single-particle dynamics in the transverse current autocorrelation function of a liquid metal

Autor(en)

Eleonora Guarini, Ubaldo Bafile, Daniele Colognesi, Alessandro Cunsolo, Alessio De Francesco, Ferdinando Formisano, Wouter Montfrooij, Martin Neumann, Fabrizio Barocchi

Abstrakt

A recent simulation study of the transverse current autocorrelation of the Lennard-Jones fluid [Guarini et al., Phys. Rev. E 107, 014139 (2023)] revealed that this function can be perfectly described within the exponential expansion theory [Barocchi et al., Phys. Rev. E 85, 022102 (2012)]. However, above a certain wavevector Q, not only transverse collective excitations were found to propagate in the fluid, but a second oscillatory component of unclear origin (therefore called X) must be considered to fully account for the time dependence of the correlation function. Here, we present an extended investigation of the transverse current autocorrelation of liquid Au as obtained by ab initio molecular dynamics in the very wide range of wavevectors 5.7 ≤ Q ≤ 32.8 nm

⁻¹ in order to also follow the behavior of the X component, if present, at large Q values. A joint analysis of the transverse current spectrum and its self-portion indicates that the second oscillatory component arises from the longitudinal dynamics, as suggested by its close resemblance with the previously determined component accounting for the longitudinal part of the density of states. We conclude that such a mode, albeit featuring a merely transverse property, fingerprints the effect of longitudinal collective excitations on single-particle dynamics, rather than arising from a possible coupling between transverse and longitudinal acoustic waves.

Organisation(en)

Computergestützte Physik und Physik der Weichen Materie

Externe Organisation(en)

Università degli Studi di Firenze, Consiglio Nazionale delle Ricerche, University of Wisconsin, Madison, Institut Laue-Langevin (ILL), University of Missouri-Columbia

Journal

Journal of Chemical Physics

Band

158

Anzahl der Seiten

9

ISSN

0021-9606

DOI

https://doi.org/10.1063/5.0152090

Publikationsdatum

06-2023

Peer-reviewed

Ja

ÖFOS 2012

103015 Kondensierte Materie, 103043 Computational Physics, 103029 Statistische Physik

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie, Physical and Theoretical Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/b39e9ab2-2cee-44de-99ab-2bb9a605786d