Active cluster crystals

  title={Active cluster crystals},
  author={Jean-Baptiste Delfau and C. Rodr'iguez L'opez and Emilio Hern'andez-Garc'ia},
  journal={New Journal of Physics},
We study the appearance and properties of cluster crystals (solids in which the unit cell is occupied by a cluster of particles) in a two-dimensional system of self-propelled active Brownian particles with repulsive interactions. Self-propulsion deforms the clusters by depleting particle density inside, and for large speeds it melts the crystal. Continuous field descriptions at several levels of approximation allow us to identify the relevant physical mechanisms. 
6 Citations

A comparative study between two models of active cluster crystals

An effective description is developed which captures some properties of the stable clusters for both ABP and AOUP, and the different phases appearing in the system, in particular, the formation of ordered patterns drifting in space without being altered.

Focus on Active Colloids and Nanoparticles

The concept of ‘active matter’ has seen a tremendous development in recent years. Its constituents, ranging from birds to cells to phoretic particles and molecular motors, constantly convert

Self-assembling outside equilibrium: emergence of structures mediated by dissipation.

It is hoped that the knowledge of the intimate mechanisms leading to the formation of structures will make the implementation of re-configurable and bio-inspired materials possible and give a simpler perspective on the understanding of the emergence of life.

Resting and traveling localized states in an active phase-field-crystal model.

A detailed analysis of the bifurcation structure of periodic and localized, resting and traveling states in a one-dimensional active PFC model is presented, where a particular focus lies on the onset of motion, where it is shown that it occurs either through a drift-pitchfork or a Drift-transcritical b ifurcation.

Cluster crystals with combined soft- and hard-core repulsive interactions

We acknowledge financial support from the Spanish Grants LAOP CTM2015-66407-P (AEI/FEDER, EU) and ESOTECOS FIS2015-63628-C2-1-R (AEI/FEDER, EU).

Active cluster crystals with Vicsek-like alignment interaction

Master’s degree in Physics of Complex Systems at the Universitat De Les Illes Balears, 2017 - 2018.



Active crystals and their stability.

It is demonstrated here that during migration, the single-crystalline texture together with the globally ordered collective motion is preserved even on large length scales, and the resulting hydrodynamic interactions can destabilize the order.

Traveling and resting crystals in active systems.

A microscopic field theory for crystallization in active systems is proposed which unifies the phase-field-crystal model of freezing with the Toner-Tu theory for self-propelled particles and provides a starting point for the design of new active materials.

Formation of polymorphic cluster phases for a class of models of purely repulsive soft spheres.

We present results from density functional theory and computer simulations that unambiguously predict the occurrence of first-order freezing transitions for a large class of ultrasoft model systems

Living clusters and crystals from low-density suspensions of active colloids.

This Letter addresses the problem of the formation of living clusters and crystals of active particles in three dimensions by studying two systems: self-propelled particles interacting via a generic attractive potential and colloids that can move toward each other as a result of active agents.

Dynamical clustering and phase separation in suspensions of self-propelled colloidal particles.

A (quasi-)two-dimensional colloidal suspension of self-propelled spherical particles propelled due to diffusiophoresis in a near-critical water-lutidine mixture finds that the driving stabilizes small clusters and undergoes a phase separation into large clusters and a dilute gas phase.

Athermal phase separation of self-propelled particles with no alignment.

This work shows that the isotropic fluid phase separates well below close packing and exhibits the large number fluctuations and clustering found ubiquitously in active systems.

Erratum: Formation of Polymorphic Cluster Phases for a Class of Models of Purely Repulsive Soft Spheres [Phys. Rev. Lett. 96, 045701 (2006)]

We present results from density functional theory and computer simulations that unambiguously predict the occurrence of first-order freezing transitions for a large class of ultrasoft model systems

Computer assembly of cluster-forming amphiphilic dendrimers.

This work shows that amphiphilic dendrimers are suitable colloids for the experimental realization of a new clustering mechanism for soft matter particles that interact via a certain kind of purely repulsive, bounded potentials, and pave the way for the synthesis of such macromolecules.

Pattern formation in self-propelled particles with density-dependent motility.

It is shown that interactions lead generically to the formation of a host of patterns, including moving clumps, active lanes, and asters, which could explain many of the patterns seen in recent experiments and simulations.

Dynamic clustering in active colloidal suspensions with chemical signaling.

The experimental results are reproduced mathematically by a chemotactic aggregation mechanism, originally introduced to account for bacterial aggregation and accounting here for diffusiophoretic chemical interaction between colloidal swimmers.