### Abstract

We study a Vicsek-style model of self-propelled particles where ferromagnetic and nematic alignment compete in both the usual "metric" version and in the "metric-free" case where a particle interacts with its Voronoi neighbors. We show that the phase diagram of this out-of-equilibrium XY model is similar to that of its equilibrium counterpart: The properties of the fully nematic model, studied before by Ginelli et al. [Phys. Rev. Lett. 104, 184502 (2010)], are thus robust to the introduction of a modest bias of interactions toward ferromagnetic alignment. The direct transitions between polar and nematic ordered phases are shown to be discontinuous in the metric case, and continuous, belonging to the Ising universality class, in the metric-free version.

Original language | English |
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Article number | 050101(R) |

Number of pages | 5 |

Journal | Physical Review. E, Statistical, Nonlinear and Soft Matter Physics |

Volume | 86 |

Issue number | 5 |

DOIs | |

Publication status | Published - 5 Nov 2012 |

### Cite this

*Physical Review. E, Statistical, Nonlinear and Soft Matter Physics*,

*86*(5), [050101(R)]. https://doi.org/10.1103/PhysRevE.86.050101

**Competing ferromagnetic and nematic alignment in self-propelled polar particles.** / Ngo, Sandrine; Ginelli, Francesco; Chate, Hugues.

Research output: Contribution to journal › Article

*Physical Review. E, Statistical, Nonlinear and Soft Matter Physics*, vol. 86, no. 5, 050101(R). https://doi.org/10.1103/PhysRevE.86.050101

}

TY - JOUR

T1 - Competing ferromagnetic and nematic alignment in self-propelled polar particles

AU - Ngo, Sandrine

AU - Ginelli, Francesco

AU - Chate, Hugues

PY - 2012/11/5

Y1 - 2012/11/5

N2 - We study a Vicsek-style model of self-propelled particles where ferromagnetic and nematic alignment compete in both the usual "metric" version and in the "metric-free" case where a particle interacts with its Voronoi neighbors. We show that the phase diagram of this out-of-equilibrium XY model is similar to that of its equilibrium counterpart: The properties of the fully nematic model, studied before by Ginelli et al. [Phys. Rev. Lett. 104, 184502 (2010)], are thus robust to the introduction of a modest bias of interactions toward ferromagnetic alignment. The direct transitions between polar and nematic ordered phases are shown to be discontinuous in the metric case, and continuous, belonging to the Ising universality class, in the metric-free version.

AB - We study a Vicsek-style model of self-propelled particles where ferromagnetic and nematic alignment compete in both the usual "metric" version and in the "metric-free" case where a particle interacts with its Voronoi neighbors. We show that the phase diagram of this out-of-equilibrium XY model is similar to that of its equilibrium counterpart: The properties of the fully nematic model, studied before by Ginelli et al. [Phys. Rev. Lett. 104, 184502 (2010)], are thus robust to the introduction of a modest bias of interactions toward ferromagnetic alignment. The direct transitions between polar and nematic ordered phases are shown to be discontinuous in the metric case, and continuous, belonging to the Ising universality class, in the metric-free version.

U2 - 10.1103/PhysRevE.86.050101

DO - 10.1103/PhysRevE.86.050101

M3 - Article

VL - 86

JO - Physical Review. E, Statistical, Nonlinear and Soft Matter Physics

JF - Physical Review. E, Statistical, Nonlinear and Soft Matter Physics

SN - 1539-3755

IS - 5

M1 - 050101(R)

ER -