Generic ordering of structural transitions in quasi-one-dimensional Wigner crystals

TL;DR

This paper studies how the shape of the confining potential affects the sequence of structural phase transitions in quasi-one-dimensional Wigner crystals, reconciling theoretical predictions with experimental observations.

Contribution

It introduces a unified analysis of transition sequences under different confinement profiles, explaining discrepancies between theory and experiment.

Findings

Transition sequences depend on the confinement potential shape.

The study explains the 1-2-3-4 sequence observed experimentally.

Theoretical predictions align with experimental results across different confinements.

Abstract

We investigate the dependence of the structural phase transitions in an infinite quasi-one-dimensional system of repulsively interacting particles on the profile of the confining channel. Three different functional expressions for the confinement potential related to real experimental systems are used that can be tuned continuously from a parabolic to a hard-wall potential in order to find a thorough understanding of the ordering of the chain-like structure transitions. We resolve the longstanding issue why the most theories predicted a 1-2-4-3-4 sequence of chain configurations with increasing density, while some experiments found the 1-2-3-4 sequence.