Pinned-to-sliding transition and structural crossovers for helically confined charges

TL;DR

This paper investigates how charged particles confined on a helix transition from being pinned to sliding under external force, revealing a structural crossover and defect formation as the helix radius increases.

Contribution

It introduces a detailed analysis of the pinned-to-sliding transition and structural crossovers in helical confined charges under non-equilibrium conditions.

Findings

Identification of a pinned-to-sliding transition with increasing external force.

Observation of a structural transition in the particle chain as helix radius increases.

Detection of multiple defects forming in the crystal structure at larger radii.

Abstract

We explore the non-equilibrium dissipative dynamics of a system of identical charged particles trapped on a closed helix. The particles are subject to an external force accelerating them along the underlying structure. The effective interactions between the charges induce a coupling of the center-of-mass to the relative motion which in turn gives rise to a pinned-to-sliding transition with increasing magnitude of the external force. In the sliding regime we observe an Ohmic behaviour signified by a constant mobility. Within the same regime a structural transition of the helical particle chain takes place with increasing the helix radius leading to a global change of the crystalline arrangement. The resulting crystal is characterized by the existence of multiple defects whose number increases with the helix radius.