Interface Roughening in Nonequilibrium Phase-Separated Systems

Area of Science:

• Physics
• Soft Matter Physics
• Statistical Mechanics

Background:

• Phase-separated systems exhibit interface roughening driven by capillary waves.
• Existing models like Edwards-Wilkinson and Kardar-Parisi-Zhang (KPZ) do not capture the nonlocal dynamics caused by bulk fluxes.

Purpose of the Study:

• To identify and characterize the universality class governing the dynamics of interfaces in active phase-separated systems.
• To investigate the theoretical framework beyond detailed balance for interface dynamics.

Main Methods:

• Derivation of effective interface dynamics from a minimal field theory of active phase separation.
• One-loop renormalization group calculations to determine scaling exponents.
• Numerical integration of the newly proposed |q|KPZ equation.

Main Results:

• Identification of a novel universality class, termed |q|KPZ, for interfaces in active phase separation.
• Computation of scaling exponents associated with the |q|KPZ universality class.
• Validation of theoretical predictions through numerical simulations.

Conclusions:

• The |q|KPZ universality class provides a new framework for understanding interface dynamics in systems out of equilibrium.
• This class is relevant for describing liquid-vapor interfaces in both 2D and 3D active systems.
• The findings extend the applicability of interface growth models to more complex, non-equilibrium phenomena.