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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 13: Glasses and Glass Transition (joint session CPP/DY)

CPP 13.5: Vortrag

Montag, 18. März 2024, 17:30–17:45, H 0107

A self-consistent current response theory of jamming and vibrational modes in low-temperature amorphous solids — •Florian Vogel, Philipp Baumgärtel, and Matthias Fuchs — University of Konstanz, Konstanz 78464, Germany

Topologically disordered solids exhibit characterisitc anomalies like sound attenuation in the absence of thermal fluctuation and deviations from Debye*s law in the density of states. We present a novel mode-coupling approach to the understanding of athermal amorphous solids, which goes beyond the usual self-consistent Born approximation. To successfully predict the correct sound attenuation, we had to take correlated fluctuations into account. The resulting first principle theory successfully describes the jammed phase. It can also be mapped to the schematic theory [1] of the Euclidean-random-matrix model introduced by Parisi and co-workers [2] and provides a sound description of the unjammed athermal phase and our predictions for the critical dynamics agree with simulations. Most importantly, we manage to describe the unjamming transition without having to rely on negative eigenvalues of the Hessian. The softness of our systems expresses itself as a vanishing dispersion relation, which always stays non-negative. Our theory is in qualitative and semi-quantitative agreement with the numerical solutions of the ERM-model.

References

[1] F. Vogel and M. Fuchs. Phys. Rev. Lett., 130:236101, 2023.

[2] M. Mézard, G. Parisi, and A. Zee. Nuclear Physics B, 559(3):689*701, 1999.

Keywords: Jamming; Mode-coupling theory; (Un-) jamming transition