Characterization of MIPS in a suspension of repulsive active Brownian particles through dynamical features

Martín‐Roca, José; Martínez, Rosa; Alexander, Lachlan C.; Diez, Angel L.; Aarts, Dirk G. A. L.; Alarcón, Francisco; Ramı́rez, Jorge; Valeriani, Chantal

doi:10.1063/5.0040141

Cited by 25 publications

(22 citation statements)

References 79 publications

(95 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the non-equilibrium phase coexistence typical of active matter, known as motility induced phase separation [43][44][45][46][47][48], is suppressed by translational inertia [49][50][51][52]. Similarly, inertial effects reduce the accumulation near boundaries or obstacles typical of active particles [53][54][55] and hinder the crystallization [56].…”

Section: Introductionmentioning

confidence: 99%

Role of rotational inertia for collective phenomena in active matter

Caprini¹,

Gupta²,

Löwen³

2022

Preprint

View full text Add to dashboard Cite

We investigate the effect of rotational inertia on the collective phenomena of underdamped active systems and show that the increase of the moment of inertia of each particle favors non-equilibrium phase coexistence, known as motility induced phase separation, and counteracts its suppression due to translational inertia. Our conclusion is supported by a non-equilibrium phase diagram (in the plane spanned by rotational inertial time and translational inertial time) whose transition line is understood theoretically through scaling arguments. In addition, rotational inertia increases the correlation length of the spatial velocity correlations in the dense cluster. The fact that rotational inertia enhances collective phenomena, such as motility induced phase separation and spatial velocity correlations, is strongly linked to the increase of rotational persistence. Moreover, large moments of inertia induce non-monotonic temporal (cross) correlations between translational and rotational degrees of freedom truly absent in non-equilibrium systems.

show abstract

Section: Introductionmentioning

confidence: 99%

Role of rotational inertia for collective phenomena in active matter

Caprini¹,

Gupta²,

Löwen³

2022

Preprint

View full text Add to dashboard Cite

show abstract

“…In this Section we focus on parameters in the MIPS region of the phase diagram (for some recent studies of this phase see [90][91][92][93][94]) where the system separates into a macroscopic dense and a dilute phase, and we investigate the defects in the dense component only. In other words, we do not consider the particles in the dilute phase nor in the bubbles within the dense one [95], even though they are most likely mis-coordinated.…”

Section: Mips and Finite Length Stringsmentioning

confidence: 99%

Unified analysis of Topological Defects in 2D systems of Active and Passive disks

Digregorio¹,

Levis²,

Cugliandolo³

et al. 2021

Preprint

View full text Add to dashboard Cite

We provide a comprehensive quantitative analysis of localized and extended topological defects in the steady state of 2D passive and active repulsive Brownian disk systems. We show that, both in and out-of-equilibrium, the passage from the solid to the hexatic is driven by the unbinding of dislocations, in quantitative agreement with the KTHNY singularity. Instead, although disclinations dissociate as soon as the liquid phase appears, extended clusters of defects largely dominate below the solid-hexatic critical line. The latter percolate in the liquid phase very close to the hexaticliquid transition, both for continuous and discontinuous transitions, in the homogeneous liquid regime. At critical percolation the clusters of defects are fractal with statistical and geometric properties that, within our numerical accuracy, are independent of the activity and compatible with the universality class of uncorrelated critical percolation. We also characterize the spatial organization of different kinds of point-like defects and we show that the disclinations are not free, but rather always very near more complex defect structures. At high activity, the bulk of the dense phase generated by Motility-Induced Phase Separation is characterized by a density of point-like defects, and statistics and morphology of defect clusters, set by the amount of activity and not the packing fraction. Hexatic domains within the dense phase are separated by grain-boundaries along which a finite network of topological defects resides, interrupted by gas bubbles in cavitation. The fractal dimension of this network diminishes for increasing activity. This structure is dynamic in the sense that the defect network allows for an unzipping mechanism that leaves free space for gas bubbles to appear, close, and even be released into the dilute phase.

show abstract

“…MIPS has been detected in experimental set-ups of active colloids 11,14–16 and thoroughly characterised in numerical simulations of active Brownian particles (ABPs). 1,5,17–23 Moreover, MIPS cannot be avoided in the presence of inertial effects, 24,25 when considering a suspension of active particles moving on a lattice, 26,27 or when an amount of passive particles is added to an active suspension. 28–30…”

Section: Introductionmentioning

confidence: 99%

“…MIPS has been detected in experimental set-ups of active colloids 11,[14][15][16] and thoroughly characterised in numerical simulations of active Brownian particles (ABPs). 1,5,[17][18][19][20][21][22][23] Moreover, MIPS cannot be avoided in the presence of inertial effects, 24,25 when considering a suspension of active particles moving on a lattice, 26,27 or when an amount of passive particles is added to an active suspension. [28][29][30] Trying to understand this non-equilibrium phase separation via a mechanical equation of state, one could draw similarities with the interfacial properties of equilibrium phases.…”

Section: Introductionmentioning

confidence: 99%