Studying Soft Matter with "Soft" Potentials: Fast Lattice Monte Carlo Simulations and Corresponding Lattice Self-Consistent Field Calculations

TL;DR

This paper introduces fast lattice Monte Carlo simulations using soft potentials for efficient sampling of confined homopolymer systems, enabling better analysis of correlation and fluctuation effects compared to traditional methods.

Contribution

It presents a novel fast lattice Monte Carlo method with soft potentials that simplifies calculations and enhances the analysis of fluctuation effects in polymer systems.

Findings

Faster relaxation and sampling in simulations.

Quantitative analysis of correlation and fluctuation effects.

Comparison with lattice field theories confirms accuracy.

Abstract

The basic idea of fast Monte Carlo (MC) simulations is to perform particle-based MC simulations with the excluded-volume interactions modeled by "soft" repulsive potentials that allow particle overlapping. This gives much faster system relaxation and better sampling of the configurational space than conventional molecular simulations with "hard" repulsions that prevent particle overlapping. Here we present fast lattice MC (FLMC) simulations for confined homopolymers, where multiple occupancy of lattice sites is allowed with a proper Boltzmann weight and thus the evaluation of nearest-neighbor interactions can also be avoided. When compared with the corresponding lattice field theories based on the \emph{same} Hamiltonian, FLMC simulations further provide a powerful means for unambiguously and quantitatively revealing the correlation/fluctuation effects.