How dissipation constrains fluctuations in nonequilibrium liquids: Diffusion, structure and biased interactions

TL;DR

This paper explores how energy dissipation influences the structure and dynamics of nonequilibrium liquids, revealing that biasing trajectories can effectively modify interactions and induce spatial organization.

Contribution

It introduces a theoretical framework linking dissipation to structure and diffusion in nonequilibrium liquids, and demonstrates how biasing can control collective behavior.

Findings

Dissipation relates directly to diffusion and correlations in nonequilibrium liquids.

Biasing trajectories can effectively renormalize interactions in the system.

Tuning dissipation offers a method to control structure and dynamics in soft materials.

Abstract

The dynamics and structure of nonequilibrium liquids, driven by non-conservative forces which can be either external or internal, generically hold the signature of the net dissipation of energy in the thermostat. Yet, disentangling precisely how dissipation changes collective effects remains challenging in many-body systems due to the complex interplay between driving and particle interactions. First, we combine explicit coarse-graining and stochastic calculus to obtain simple relations between diffusion, density correlations and dissipation in nonequilibrium liquids. Based on these results, we consider large-deviation biased ensembles where trajectories mimic the effect of an external drive. The choice of the biasing function is informed by the connection between dissipation and structure derived in the first part. Using analytical and computational techniques, we show that biasing trajectories effectively renormalizes interactions in a controlled manner, thus providing intuition on how driving forces can lead to spatial organization and collective dynamics. Altogether, our results show how tuning dissipation provides a route to alter the structure and dynamics of liquids and soft materials.