Local Melting and Drag for a Particle Driven Through a Colloidal Crystal

TL;DR

This study uses numerical simulations to explore how a colloidal particle's movement through a colloidal crystal causes local melting, defect formation, and increased drag, with implications for understanding vortex behavior in superconductors.

Contribution

It reveals the conditions under which local melting occurs and links defect generation and drag increase to temperature and particle charge, providing new insights into colloidal and vortex dynamics.

Findings

Local melting occurs near the driven particle at high charge ratios.

Defect generation correlates with increased drag force.

Results resemble vortex peak effect phenomena in superconductors.

Abstract

We numerically investigate a colloidal particle driven through a colloidal crystal as a function of temperature. When the charge of the driven particle is larger or comparable to that of the colloids comprising the crystal, a local melting can occur, characterized by defect generation in the lattice surrounding the driven particle. The generation of the defects is accompanied by an increase in the drag force on the driven particle, as well as large noise fluctuations. We discuss the similarities of these results to the peak effect phenomena observed for vortices in superconductors.