Understanding Plastic Deformation in Thermal Glasses from Single-Soft-Spot Dynamics

Sam S. Schoenholz, Andrea J. Liu, Robert A. Riggleman, Joerg Rottler. Physical Review X 4: 031014 (2014)


By considering the low-frequency vibrational modes of amorphous solids, Manning and Liu [Phys. Rev. Lett. 107, 108302 (2011)] showed that a population of “soft spots” can be identified that are intimately related to plasticity at zero temperature under quasistatic shear. In this work, we track individual soft spots with time in a two-dimensional sheared thermal Lennard Jones glass at temperatures ranging from deep in the glassy regime to above the glass transition temperature. We show that the lifetimes of individual soft spots are correlated with the time scale for structural relaxation. We additionally calculate the number of rearrangements required to destroy soft spots and show that most soft spots can survive many rearrangements. Finally, we show that soft spots are robust predictors of rearrangements at temperatures well into the supercooled regime. Altogether, these results pave the way for mesoscopic theories of plasticity of amorphous solids based on dynamical behavior of individual soft spots.

Related Research Topics

Dynamics of glass-forming materials