Quantum Analog of Vicsek Model for Active Matter

TL;DR

This paper introduces a quantum analog of the Vicsek model using spin-1/2 particles, revealing quantum flocking behavior and connecting classical active matter models to quantum systems.

Contribution

It presents a quantum model that converges to classical flocking models, bridging quantum physics and active matter research with novel insights.

Findings

Quantum model exhibits spontaneous magnetization and flocking order.

Converges to Vicsek and Toner-Tu models in classical and continuous limits.

Opens new avenues for quantum active matter research.

Abstract

We propose a quantum model consisting of an ensemble of overdamped spin$-1/2$ particles with ferromagnetic couplings, driven by a radially homogeneous magnetic field. The spontaneous magnetization of the spin components breaks the $SO(3)$ (or $SO(2)$) symmetry, inducing an ordered phase of flocking. Our model converges to the Vicsek model in the classical limit and corresponds to the Toner-Tu model in the continuous limit. Our investigation not only elucidates the intrinsic connection between these two models, but also introduces new opportunities for exploring the mechanisms underlying flocking order and correlations at the quantum level, which maybe pave the way for a new field of research -- the quantum active matter.