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arXiv · 2303.07147

Enhanced Vibrational Stability in Glass Droplets

Surajit Chakraborty·Vishnu V. Krishnan·Kabir Ramola·Smarajit Karmakar
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Abstract

We show through simulations of amorphous solids prepared in open boundary conditions that they possess significantly fewer low-frequency vibrational modes compared to their periodic boundary counterparts. Specifically, using measurements of the vibrational density of states, we find that the $D(\omega) \sim \omega^4$ law changes to $D(\omega) \sim \omega^\delta$ with $\delta \approx 5$ in two dimensions and $\delta \approx 4.5$ in three dimensions. Crucially, this enhanced stability is achieved when utilizing slow annealing protocols to generate solid configurations. We perform an anharmonic analysis of the minima corresponding to the lowest-frequency modes in such open-boundary systems and discuss their correlation with the density of states. A study of various system sizes further reveals that small systems display a higher degree of localization in vibrations. Lastly, we confine open-boundary solids in order to introduce macroscopic stresses in the system which are absent in the unconfined system, and find that the $D(\omega) \sim \omega^4$ behavior is recovered.

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Surajit Chakraborty, Vishnu V. Krishnan, Kabir Ramola, Smarajit Karmakar. 2023-03-13. Enhanced Vibrational Stability in Glass Droplets. https://doi.org/10.1093/pnasnexus/pgad289

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