2019/11/30 by Corrado Rainone, Eran Bouchbinder, Edan Lerner
Computer Science · Materials Science · Physics and Astronomy · #Algorithm #Artificial intelligence #Computer science #Liquid Crystal Research Advancements #Material Dynamics and Properties #Materials science #Nonlinear Dynamics and Pattern Formation #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1073/pnas.1919958117
published as PNAS 117, 5228 (2020) · slightly revised title, extended theoretical discussion, extended data set (higher temperatures, revised figures) and a new figure (Fig. 3)
openalex publication_date 2020/02/24 · arxiv created 2020/02/26 · arxiv updated 2021/03/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is now well established that glasses feature quasilocalized nonphononic excitations-coined "soft spots"-, which follow a universal [Formula: see text] density of states in the limit of low frequencies ω. All glass-specific properties, such as the dependence on the preparation protocol or composition, are encapsulated in the nonuniversal prefactor of the universal [Formula: see text] law. The prefactor, however, is a composite quantity that incorporates information both about the number of quasilocalized nonphononic excitations and their characteristic stiffness, in an apparently inseparable manner. We show that by pinching a glass-i.e., by probing its response to force dipoles-one can disentangle and independently extract these two fundamental pieces of physical information. This analysis reveals that the number of quasilocalized nonphononic excitations follows a Boltzmann-like law in terms of the parent temperature from which the glass is quenched. The latter, sometimes termed the fictive (or effective) temperature, plays important roles in nonequilibrium thermodynamic approaches to the relaxation, flow, and deformation of glasses. The analysis also shows that the characteristic stiffness of quasilocalized nonphononic excitations can be related to their characteristic size, a long sought-for length scale. These results show that important physical information, which is relevant for various key questions in glass physics, can be obtained through pinching a glass.