Year: 2026
Type: article
Abstract: Chirality in active and passive fluids gives rise to odd transport properties, most notably the emergence of robust edge currents that defy standard dissipative dynamics. While these phenomena are well-described by continuum hydrodynamics, the topological analogy with quantum systems, widely invoked to explain their robustness, has lacked a concrete discrete realization. Here, we present a lattice model for an isotropic chiral random walk that bridges the gap between classical stochastic diffusion and unitary quantum evolution. By equipping the walker with an internal degree of freedom and a tunable chirality parameter, p , we interpolate between a standard diffusive random walk and a deterministic, topologically non-trivial quantum walk. We show that signatures of the topologically protected edge states characteristic of the unitary limit ( p = 1 ) persist into the dissipative regime ( p < 1 ) This correspondence allows us to theoretically ground the robustness of edge flows in classical chiral systems using the bulk-boundary correspondence of Floquet topological insulators. Our results provide a discrete, effective description for odd diffusion, offering a powerful toolkit to predict transport in confined geometries and disordered chiral media.
Source: New Journal of Physics
Authors: Jan Wójcik, Erik Kalz
Institutions: University of Gdańsk, University of Potsdam
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,610
OpenAlex ID: W7216175506