Coupling spin to velocity: collective motion of Hamiltonian polar particles

@article{Bore2015CouplingST,
  title={Coupling spin to velocity: collective motion of Hamiltonian polar particles},
  author={Sigbj{\o}rn L{\o}land Bore and Michael Schindler and Khanh-Dang Nguyen Thu Lam and Eric Bertin and Olivier Dauchot},
  journal={arXiv: Statistical Mechanics},
  year={2015}
}
We propose a conservative two-dimensional particle model in which particles carry a continuous and classical spin. The model includes standard ferromagnetic interactions between spins of two different particles, and a nonstandard coupling between spin and velocity of the same particle inspired by the coupling observed in self-propelled hard discs. Because of this coupling Galilean invariance is broken and the conserved linear momentum associated to translation invariance is not proportional to… 

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