Nonlinear response theory of molecular machines

¹ Max Planck Institute for Dynamics and Self-Organization (MPI-DS) - D-37077 Göttingen, Germany
² Department of Physics and Astronomy, University College London - London WC1E 6BT, UK
³ Rudolf Peierls Centre for Theoretical Physics, University of Oxford - Oxford OX1 3PU, UK

Received: 22 May 2024
Accepted: 2 August 2024

Abstract

Chemical affinities are responsible for driving active matter systems out of equilibrium. At the nano-scale, molecular machines interact with the surrounding environment and are subjected to external forces. The mechano-chemical coupling which arises naturally in these systems reveals a complex interplay between chemical and mechanical degrees of freedom with strong impact on their active mechanism. By considering various models far from equilibrium, we show that the tuning of applied forces gives rise to a nonlinear response that causes a non-monotonic behaviour in the machines’ activity. Our findings have implications in understanding, designing, and triggering such processes by controlled application of external fields, including the collective dynamics of larger non-equilibrium systems where the total dissipation and performance might be affected by internal and inter-particle interactions.