Year: 2025
Type: article
Abstract: Can activity be transmitted from smaller to larger scales? We report on such a transfer from a homogeneous active medium to a Newtonian spherical probe. The active medium consists of faster and dilute self-propelled particles, modeled as run-and-tumble particles in 1D or as active Brownian particles in 2D. We derive the reduced fluctuating dynamics of the probe, valid for arbitrary probe velocity, characterized by velocity-dependent friction and noise. In addition to a standard passive regime, we identify peculiar active regimes where the probe becomes self-propelled with high persistence, and its velocity distribution begets peaks at nonzero values. These features are quantitatively confirmed by numerical simulations of the composite probe-medium system. The emergence of active regimes depends not only on the far-from-equilibrium nature of the medium but also on the probe-medium coupling. Our findings reveal how, solely via the induced friction and noise, persistence can cross different scales to transfer active motion.
Source: Physical Review Letters
DOI: 10.1103/bwk3-3nmn
Authors: Ji-Hui Pei, Christian Maes
Institutions: Peking University, KU Leuven
Language: English
Topic: Micro and Nano Robotics
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funder: China Scholarship Council
Award: G6224826974
OpenAlex ID: W4415025600