Landscape-Inversion Phase Transition in Dipolar Colloids: Tuning the Structure and Dynamics of 2D Crystals

TL;DR

This paper investigates a novel phase transition in 2D dipolar colloidal crystals, revealing how external magnetic fields can precisely control their structure and dynamics through a landscape-inversion mechanism.

Contribution

It introduces a new first-order phase transition mechanism involving energy landscape inversion, enabling tunable crystal symmetry and dynamic properties in dipolar colloids.

Findings

Demonstrates control of crystal symmetry via magnetic field tuning

Reveals dynamic property modulation through field adjustments

Shows non-standard phase-ordering with metastable domain formation

Abstract

We study the 2D crystalline phases of paramagnetic colloidal particles with dipolar interactions and constrained on a periodic substrate. Combining theory, simulation, and experiments we demonstrate a new scenario of first-order phase transitions that occurs via a complete inversion of the energy landscape, featuring non-conventional properties that allow for: (i) tuning of crystal symmetry; (ii) control of dynamical properties of different crystalline orders via tuning of their relative stability with an external magnetic field; (iii) an equivalent but independent control of the same dynamic properties via temporal modulations of that field; and (iv) non-standard phase-ordering kinetics involving spontaneous formation of transient metastable domains.