Tagged particle dynamics in supercooled quantum liquid

Abstract

We analyze dynamics of quantum supercooled liquids in terms of tagged particle dynamics. Unlike the classical case, uncertainty in the position of a particle in quantum liquid leads to qualitative changes. We demonstrate these effects in the dynamics of the first two moments of displacements, namely, the mean-squared displacement, $⟨\Delta r^2(t)⟩$, and $⟨\Delta r^4(t)⟩$. Results are presented for a hard sphere liquid using mode-coupling theory (MCT) formulation and simulation on a binary Lennard-Jones liquid. As the quantumness (controlled by the de-Broglie thermal wavelength) is increased, a non-zero value of the moments at zero time leads to significant deviations from the classical behavior in the initial dynamics. Initial displacement shows ballistic behavior $⟨\Delta r^2(t)⟩\sim t^2$, but, as a result of large uncertainty in the position, the dynamical effects become weaker with increasing quantumness over this time scale.

References in corpus (5)

• Dynamical heterogeneities in a supercooled Lennard-Jones liquid
• Asymptotic laws for tagged-particle motion in glassy systems
• Quantum fluctuations can promote or inhibit glass formation
• Theory and simulations of quantum glass forming liquids
• Structural relaxation in quantum supercooled liquids: A mode-coupling approach

Cited by in corpus (1)

• Quantum fluctuations can enhance or reduce positional uncertainty at finite temperature