Author(s): Jessica Metzger, Sunghan Ro, and Julien Tailleur The emergence of nonequilibrium currents has attracted a lot of attention. The “ratchet principle” identifies the violation of any form of parity and time-reversal symmetries as the necessary conditions for the emergence of such currents. Here we study active and passive systems with asymmetric spat… [Phys. Rev. Lett. 136, 257102] Published Fri Jun 26, 2026