Localization phenomena in models of ion-conducting glass formers

TL;DR

This study investigates localization phenomena in ion-conducting glass models, revealing a distinct small-particle localization transition and comparing it with the Lorentz gas, highlighting similarities and differences in transport behavior.

Contribution

It provides new insights into localization transitions in soft-sphere mixtures and their relation to the Lorentz gas model through molecular dynamics simulations.

Findings

Small particles exhibit anomalous diffusion indicating a localization transition.

Switching off excluded volume constraints affects small-particle dynamics.

Qualitative similarities and differences between the soft-sphere mixture and Lorentz gas localization transitions.

Abstract

The mass transport in soft-sphere mixtures of small and big particles as well as in the disordered Lorentz gas (LG) model is studied using molecular dynamics (MD) computer simulations. The soft-sphere mixture shows anomalous small-particle diffusion signifying a localization transition separate from the big-particle glass transition. Switching off small-particle excluded volume constraints slows down the small-particle dynamics, as indicated by incoherent intermediate scattering functions. A comparison of logarithmic time derivatives of the mean-squared displacements reveals qualitative similarities between the localization transition in the soft-sphere mixture and its counterpart in the LG. Nevertheless, qualitative differences emphasize the need for further research elucidating the connection between both models.