IMSc Webinar

Plastic Instabilities and Density of Low-frequency States in Amorphous Solids

Prasenjit Das

Georg-August-Universität Göttingen

In this talk, I will describe plastic instabilities and the density of low-frequency quasi-localized modes (QLMs) in amorphous solids at T=0 and finite temperatures. For athermal solids (T=0), we study plastic instabilities by using the bare Hessian matrix and its eigenvalues and eigenfunctions. The density of low-frequency QLMs exhibits a universal density of states D(ω)~ω^4. Similar to athermal solids, we observed that the time-averaged particle configurations undergo sharp plastic instabilities under strain at finite temperatures. In this talk, I will describe the uplifting of Hessian methods to thermal glasses and show that the effective Hessian describing plastic instabilities at finite T is different from bare Hessian at T=0. Also, we found that the density of low-frequency QLMs at finite T conforms to the universal law: D(ω)~ω^4.

References:

1) Prasenjit Das, Valery Ilyin, and Itamar Procaccia, Phys. Rev. E 100 062103 (2019).
2) Prasenjit Das, H. George E. Hentschel, and Itamar Procaccia, Phys. Rev. E 101 052903 (2020).
3) Prasenjit Das, H. George E. Hentschel, Edan Lerner, and Itamar Procaccia, Phys. Rev. B 102014202 (2020).
2) Prasenjit Das and Itamar Procaccia, Phys. Rev. Lett. 126 085502 (2021).

Google Meet link : meet.google.com/chd-yfyc-eyd