This paper generalizes isomorph theory to systems that are not in thermal equilibrium. The systems are assumed to be R-simple, i.e., to have a potential energy that as a function of all particle coordinates R obeys the hidden-scale-invariance condition U(Ra) < U(Rb) ⇒ U(λRa) < U(λRb). “Systemic isomorphs” are introduced as lines of constant excess entropy in the phase diagram defined by density and systemic temperature, which is the temperature of the equilibrium state point with the average potential energy equal to U(R). The dynamics is invariant along a systemic isomorph if there is a constant ratio between the systemic and the bath temperature. In thermal equilibrium, the systemic temperature is equal to the bath temperature and the original isomorph formalism is recovered. The new approach rationalizes within a consistent framework previously published observations of isomorph invariance in simulations involving nonlinear steady-state shear flows, zero-temperature plastic flows, and glass-state isomorphs. This paper relates briefly to granular media, physical aging, and active matter. Finally, we discuss the possibility that the energy unit defining the reduced quantities should be based on the systemic rather than the bath temperature.
Skip Nav Destination
Article navigation
7 October 2020
Research Article|
October 01 2020
Isomorph theory beyond thermal equilibrium
Jeppe C. Dyre
Jeppe C. Dyre
a)
Glass and Time, IMFUFA, Department of Science and Environment, Roskilde University
, P.O. Box 260, DK-4000 Roskilde, Denmark
a)Author to whom correspondence should be addressed: [email protected]
Search for other works by this author on:
a)Author to whom correspondence should be addressed: [email protected]
J. Chem. Phys. 153, 134502 (2020)
Article history
Received:
August 05 2020
Accepted:
September 10 2020
Citation
Jeppe C. Dyre; Isomorph theory beyond thermal equilibrium. J. Chem. Phys. 7 October 2020; 153 (13): 134502. https://doi.org/10.1063/5.0024212
Download citation file:
Pay-Per-View Access
$40.00
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Citing articles via
DeePMD-kit v2: A software package for deep potential models
Jinzhe Zeng, Duo Zhang, et al.
Beyond the Debye–Hückel limit: Toward a general theory for concentrated electrolytes
Mohammadhasan Dinpajooh, Nadia N. Intan, et al.
Related Content
Bounded inverse power potentials: Isomorphism and isosbestic points
J. Chem. Phys. (April 2019)
Isomorph invariance of Couette shear flows simulated by the SLLOD equations of motion
J. Chem. Phys. (April 2013)
The EXP pair-potential system. II. Fluid phase isomorphs
J. Chem. Phys. (September 2018)
Testing the isomorph invariance of the bridge functions of Yukawa one-component plasmas
J. Chem. Phys. (January 2021)
A test for the existence of isomorphs in glass-forming materials
J. Chem. Phys. (August 2017)