Glass transition of charged particles in two-dimensional confinement

TL;DR

This study uses mode-coupling theory to analyze the glass transition of charged particles in two-dimensional confinement, comparing isotropic and anisotropic interactions relevant to experimental plasma systems.

Contribution

It introduces a theoretical comparison of glass transition behavior for charged particles with different effective interactions in 2D systems, including experimentally relevant anisotropic effects.

Findings

Isotropic Yukawa interactions lead to a certain glass transition behavior.

Anisotropic interactions cause different transition characteristics.

Parameter scans reveal how plasma conditions influence the glass transition.

Abstract

The glass transition of mesoscopic charged particles in two-dimensional confinement is studied by mode-coupling theory. We consider two types of effective interactions between the particles, corresponding to two different models for the distribution of surrounding ions that are integrated out in coarse-grained descriptions. In the first model, a planar monolayer of charged particles is immersed in an unbounded isotropic bath of ions, giving rise to an isotropically screened Debye-H\"uckel- (Yukawa-) type effective interaction. The second, experimentally more relevant system is a monolayer of negatively charged particles that levitate atop a flat horizontal electrode, as frequently encountered in laboratory experiments with complex (dusty) plasmas. A steady plasma current towards the electrode gives rise to an anisotropic effective interaction potential between the particles, with an algebraically long-ranged in-plane decay. In a comprehensive parameter scan that covers the typical range of experimentally accessible plasma conditions, we calculate and compare the mode-coupling predictions for the glass transition in both kinds of systems.