Quantum fluctuations, the Boson peak, and the glassy state of biomolecules

TL;DR

This paper demonstrates that quantum fluctuations significantly influence the glassy state of hydrated biomolecules, especially at low hydration, linking Boson peak features to quantum effects and material anisotropy.

Contribution

It reveals the fundamental role of quantum fluctuations in the glassy state of biomolecules and introduces a method to classify quantum contributions based on Boson peak behavior.

Findings

Quantum fluctuations affect the glassy state at low hydration levels.

A linear relationship exists between quantum effects and Boson peak frequency dependence.

Boson peak spectral structure correlates with material elastic anisotropy.

Abstract

It has been recognized in the literature that some physical properties of hydrated biomolecules, e.g., the occurrence of Boson peak, resembles of those of glassy state. In the present work is shown that quantum fluctuations play a fundamental role on describing the glassy state of biomolecules, specially at lower hydration levels. It is reported a remarkable linear dependence on the quantumness and the slope of the Boson peak frequency temperature dependence which would be used to classify de degree of quantum contributions to the glassy state by glasses in general. Finally, it is shown that the Boson peak two-bands spectral structure observed in some cases could be direct linked to the anisotropy of the material elastic properties.