Stability of periodic domain structures in a two-dimensional dipolar model

TL;DR

This paper studies the stability and transitions of periodic domain structures in a 2D dipolar model, revealing phase changes between striped and droplet arrangements and analyzing their stability against distortions.

Contribution

It provides a detailed analysis of the stability of different domain structures and the transition mechanisms in a 2D dipolar system, including the effects of boundary distortions.

Findings

Striped domain structures are stable near half filling.

Transition to hexagonal droplet lattices occurs with changing area fraction.

Hexagonal distortions significantly affect droplet stability.

Abstract

We investigate the energetic ground states of a model two-phase system with 1/r^3 dipolar interactions in two dimensions. The model exhibits spontaneous formation of two kinds of periodic domain structure. A striped domain structure is stable near half filling, but as the area fraction is changed, a transition to a hexagonal lattice of almost-circular droplets occurs. The stability of the equilibrium striped domain structure against distortions of the boundary is demonstrated, and the importance of hexagonal distortions of the droplets is quantified. The relevance of the theory for physical surface systems with elastic, electrostatic, or magnetostatic 1/r^3 interactions is discussed.