Structural relaxation in quantum supercooled liquids: A mode-coupling approach

TL;DR

This paper investigates how quantum effects influence the dynamics of supercooled liquids, revealing that increased quantum behavior accelerates relaxation and raises the glass transition density, with a detailed mode-coupling analysis.

Contribution

It introduces a quantum mode-coupling framework to analyze supercooled quantum liquids, highlighting the impact of quantum tunneling on relaxation dynamics and glass transition.

Findings

Classical cage effects slow down dynamics in moderate quantum regime.

Quantum tunneling accelerates relaxation in strongly quantum regime.

Power-law relaxation time increases with density, with an exponent dependent on quantumness.

Abstract

We study supercooled dynamics in quantum hard-sphere liquid using quantum mode-coupling formulation. In the moderate quantum regime, classical cage effects lead to slower dynamics compared to strongly quantum regime, where tunneling overcomes classical caging, leading to faster relaxation. As a result, the glass transition critical density can become significantly higher than for the classical liquids. Perturbative approach is used to solve time dependent quantum mode-coupling equations to study in detail the dynamics of the supercooled liquid in moderate quantum regime. Similar to the classical case, relaxation time shows power-law increase with increasing density in the supercooled regime. However, the power-law exponent is found to be dependent on the quantumness; it increases linearly as the quantumness is increased in the moderate quantum regime.