Data-driven reaction coordinate discovery in overdamped and non-conservative systems: application to optical matter...

Area of Science:

• Physics and Physical Chemistry
• Soft Matter Physics
• Nanotechnology

Background:

• Optical matter (OM) systems comprise nanoparticles in solution that self-organize via electrodynamic interactions.
• These systems exhibit non-conservative forces and overdamped dynamics, leading to diffusive particle trajectories.
• Understanding collective modes and transition mechanisms in such systems is crucial for their control and application.

Purpose of the Study:

• To propose and validate a novel data-driven approach for analyzing non-conservative, overdamped systems like optical matter.
• To determine collective modes and identify reaction coordinates governing structural transitions in OM.
• To provide a method for understanding and potentially controlling complex nanoparticle dynamics.

Main Methods:

• Utilized principal components analysis (PCA) to identify collective modes within the system dynamics.
• Employed harmonic linear discriminant analysis (HLDA) on time trajectories to estimate the reaction coordinate for structural changes.
• Validated the approach using electrodynamics-Langevin dynamics simulations of six electrodynamically-bound nanoparticles under laser illumination.

Main Results:

• The PCA-HLDA method successfully identified collective modes and a reaction coordinate for structural transitions.
• The discovered reaction coordinate showed excellent agreement with rigorous committor analysis.
• The mechanism for structural isomerization derived from the analysis closely matched experimental observations.

Conclusions:

• The data-driven PCA-HLDA approach is effective for discovering reaction coordinates in non-conservative, overdamped systems.
• This methodology aids in elucidating the fundamental mechanisms driving structural changes in optical and active matter.
• The findings pave the way for enhanced understanding and control of complex self-organizing nanoparticle systems.