Pattern Formation in Quantum Ferrofluids: from Supersolids to Superglasses

TL;DR

This paper explores the diverse pattern formations in quantum ferrofluids, revealing a rich phase diagram with supersolids, honeycomb, labyrinthine, and pumpkin phases, driven by dipolar interactions and beyond mean-field effects.

Contribution

It provides a theoretical analysis of the phase diagram of quantum ferrofluids, identifying new exotic states and scaling relations across different trap geometries and interaction parameters.

Findings

Identification of supersolid crystals at low densities

Discovery of honeycomb and labyrinthine states at higher densities

Establishment of scaling relations for pattern formation

Abstract

Pattern formation is a ubiquitous phenomenon observed in nonlinear and out-of-equilibrium systems. In equilibrium, quantum ferrofluids formed from ultracold atoms were recently shown to spontaneously develop coherent density patterns, manifesting a supersolid. We theoretically investigate the phase diagram of such quantum ferrofluids in oblate trap geometries and find an even wider range of exotic states of matter. Two-dimensional supersolid crystals formed from individual ferrofluid quantum droplets dominate the phase diagram at low densities. For higher densities we find honeycomb and labyrinthine states, as well as a pumpkin phase. We discuss scaling relations which allow us to find these phases for a wide variety of trap geometries, interaction strengths, and atom numbers. Our study illuminates the origin of the various possible patterns of quantum ferrofluids and shows that their occurrence is generic of strongly dipolar interacting systems stabilized by beyond mean-field effects.