2017/08/02 by Benjamin Loewe, Anton Souslov, Paul M. Goldbart +1
Engineering · Materials Science · Physics and Astronomy · #Active matter #Characterization and Applications of Magnetic Nanoparticles #Connection (principal bundle) #Coupling (piping) #Flocking (texture) #Heisenberg picture #Identical particles #Micro and Nano Robotics #Pickering emulsions and particle stabilization #Quantum #Spins #cond-mat.soft #cond-mat.stat-mech
paper · pdf · doi:10.1088/1367-2630/aa9cdc
published as New Journal of Physics 20, 013020 (2018) · 13 pages, 3 figures
arxiv created 2017/08/02 · openalex created_date 2017/08/17 · openalex publication_date 2017/11/27 · arxiv updated 2018/03/02 · openalex updated_date 2026/08/06
Systems composed of strongly interacting self-propelled particles can form a spontaneously flowing polar active fluid. The study of the connection between the microscopic dynamics of a single such particle and the macroscopic dynamics of the fluid can yield insights into experimentally realizable active flows, but this connection is well understood in only a few select cases. We introduce a model of self-propelled particles based on an analogy with the motion of electrons that have strong spin–orbit coupling. We find that, within our model, self-propelled particles are subject to an analog of the Heisenberg uncertainty principle that relates translational and rotational noise. Furthermore, by coarse-graining this microscopic model, we establish expressions for the coefficients of the Toner–Tu equations—the hydrodynamic equations that describe an active fluid composed of these 'active spins.' The connection between stochastic self-propelled particles and quantum particles with spin may help realize exotic phases of matter using active fluids via analogies with systems composed of strongly correlated electrons.