Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Fluctuating hydrodynamics of chiral active fluids

Journal Article · · Nature Physics
Active materials are characterized by continuous injection of energy at the microscopic level and typically cannot be adequately described by equilibrium thermodynamics. Here we study a class of active fluids in which equilibrium-like properties emerge when fluctuating and activated degrees of freedom are statistically decoupled, such that their mutual information is negligible. We analyse three paradigmatic systems: chiral active fluids composed of spinning frictional particles that are free to translate, oscillating granular gases and active Brownian rollers. In all of these systems, a single effective temperature generated by activity parameterizes both the equation of state and the emergent Boltzmann statistics. The same effective temperature, renormalized by velocity correlations, relates viscosities to steady-state stress fluctuations via a Green–Kubo relation. To rationalize these observations, we develop a theory for the fluctuating hydrodynamics of these non-equilibrium fluids and validate it through large-scale molecular dynamics simulations. Our work sheds light on the microscopic origin of odd viscosities and stress fluctuations characteristic of parity-violating fluids, in which mirror symmetry and detailed balance are broken.
Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
Army Research Office; National Science Foundation (NSF); Simons Foundation
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
1854338
Journal Information:
Nature Physics, Journal Name: Nature Physics Journal Issue: 11 Vol. 17; ISSN 1745-2473
Publisher:
Nature Publishing Group (NPG)Copyright Statement
Country of Publication:
United States
Language:
English

References (79)

Fast Parallel Algorithms for Short-Range Molecular Dynamics journal March 1995
Cohesive, frictional powders: contact models for tension journal March 2008
Stress, stress asymmetry and couple stress: from discrete particles to continuous fields journal March 2010
Transverse momentum transport in viscous flow of diatomic gases in a magnetic field journal April 1966
The approximate nature of the Onsager-Casimir reciprocal relations journal April 1983
Statistical Mechanics of Nonequilibrium Liquids book January 2008
Projection-operator methods for classical transport in magnetized plasmas. Part 1. Linear response, the Braginskii equations and fluctuating hydrodynamics journal July 2018
Odd Viscosity journal August 1998
Angular Momentum of Continua journal October 1961
Dynamic self-assembly of magnetized, millimetre-sized objects rotating at a liquid–air interface journal June 2000
Testing the thermodynamic approach to granular matter with a numerical model of a decisive experiment journal February 2002
Observing brownian motion in vibration-fluidized granular matter journal August 2003
Statistical mechanics of a gas-fluidized particle journal February 2004
In and out of equilibrium journal January 2005
Non-equilibrium glass transitions in driven and active matter journal March 2013
Odd viscosity in chiral active fluids journal November 2017
Rotating robots move collectively and self-organize journal March 2018
Manipulation of emergent vortices in swarms of magnetic rollers journal June 2018
The odd free surface flows of a colloidal chiral fluid journal September 2019
Thermodynamic uncertainty relations constrain non-equilibrium fluctuations journal November 2019
Odd elasticity journal March 2020
Emergence of lanes and turbulent-like motion in active spinner fluid journal May 2021
Rotating crystals of magnetic Janus colloids journal January 2015
Fluid Mechanical Aspects of Antisymmetric Stress journal January 1964
Ensemble Method in the Theory of Irreversibility journal November 1960
The Statistical Mechanical Theory of Transport Processes. IV. The Equations of Hydrodynamics journal June 1950
Irreversible Thermodynamics of a Fluid System with Spin journal April 1967
Group Theory and Physics journal June 1995
On the fluctuation-dissipation relation in non-equilibrium and non-Hamiltonian systems journal August 2019
Spatiotemporal order and emergent edge currents in active spinner materials journal November 2016
Effective temperature concept evaluated in an active colloid mixture journal July 2017
Hydrodynamics of random-organizing hyperuniform fluids journal October 2019
On the generalized hydrodynamics of polyatomic fluids journal October 1976
Stochastic thermodynamics, fluctuation theorems and molecular machines journal November 2012
Chiral active matter: microscopic ‘torque dipoles’ have more than one hydrodynamic description journal November 2019
Work fluctuations for a Brownian particle between two thermostats journal June 2006
Violation of the Einstein relation in granular fluids: the role of correlations journal August 2007
The effective temperature journal November 2011
Kubo formulas for viscosity: Hall viscosity, Ward identities, and the relation with conductivity journal December 2012
Time-reversal symmetry breaking in two-dimensional nonequilibrium viscous fluids journal May 2020
Stochastic rotation dynamics. I. Formalism, Galilean invariance, and Green-Kubo relations journal June 2003
Fluctuation-dissipation relations in driven dissipative systems journal April 2006
Effective temperature of active matter journal May 2008
Green-Kubo relation for viscosity tested using experimental data for a two-dimensional dusty plasma journal October 2011
Hidden entropy production and work fluctuations in an ideal active gas journal August 2018
Dancing Volvox : Hydrodynamic Bound States of Swimming Algae journal April 2009
Experimental Verification of a Modified Fluctuation-Dissipation Relation for a Micron-Sized Particle in a Nonequilibrium Steady State journal July 2009
Generalized Fluctuation-Dissipation Theorem for Steady-State Systems journal August 2009
Sedimentation and Effective Temperature of Active Colloidal Suspensions journal August 2010
Hall Viscosity and Electromagnetic Response journal February 2012
Emergent Collective Phenomena in a Mixture of Hard Shapes through Active Rotation journal February 2014
Anomalous Hydrodynamics of Two-Dimensional Vortex Fluids journal July 2014
Fast-Moving Bacteria Self-Organize into Active Two-Dimensional Crystals of Rotating Cells journal April 2015
Collective Dynamics in a Binary Mixture of Hydrodynamically Coupled Microrotors journal May 2015
How Far from Equilibrium Is Active Matter? journal July 2016
Overestimation of Viscosity by the Green-Kubo Method in a Dusty Plasma Experiment journal May 2017
Topological Waves in Fluids with Odd Viscosity journal March 2019
Rotating Membrane Inclusions Crystallize Through Hydrodynamic and Steric Interactions journal October 2019
Active Viscoelasticity of Odd Materials journal March 2021
Odd Viscosity in Active Matter: Microscopic Origin and 3D Effects journal July 2021
Velocity Fluctuations in a Homogeneous 2D Granular Gas in Steady State journal October 2000
Motor-Driven Dynamics in Actin-Myosin Networks journal December 2001
A Chiral Granular Gas journal May 2005
Equality Connecting Energy Dissipation with a Violation of the Fluctuation-Response Relation journal September 2005
On Onsager's Principle of Microscopic Reversibility journal April 1945
Granular solids, liquids, and gases journal October 1996
Built upon sand: Theoretical ideas inspired by granular flows journal January 1999
Granular matter: a tentative view journal March 1999
Nonequilibrium strongly hyperuniform fluids of circle active particles with large local density fluctuations journal January 2019
A Self-Organized Vortex Array of Hydrodynamically Entrained Sperm Cells journal July 2005
Equilibrium Regained: From Nonequilibrium Chaos to Statistical Mechanics journal January 2000
Measuring Hall viscosity of graphene’s electron fluid journal February 2019
Low rattling: A predictive principle for self-organization in active collectives journal January 2021
Statistical-Mechanical Theory of Irreversible Processes. II. Response to Thermal Disturbance journal November 1957
On Quantum Theory of Transport Phenomena: Steady Diffusion journal December 1958
Transport, Collective Motion, and Brownian Motion journal March 1965
Motility-Induced Phase Separation journal March 2015
Fluctuation-dissipation theorem in nonequilibrium steady states journal January 2010
Data and code for the publication of "Fluctuating hydrodynamics of chiral active fluids" dataset January 2021

Similar Records

Time-reversal symmetry breaking in two-dimensional nonequilibrium viscous fluids
Journal Article · Tue May 26 20:00:00 EDT 2020 · Physical Review. E · OSTI ID:1783097

Odd Diffusivity of Chiral Random Motion
Journal Article · Thu Oct 21 20:00:00 EDT 2021 · Physical Review Letters · OSTI ID:1899123

Time reversal symmetry breaking and odd viscosity in active fluids: Green–Kubo and NEMD results
Journal Article · Thu May 28 20:00:00 EDT 2020 · Journal of Chemical Physics · OSTI ID:1676376