Charge-Induced Polarization in Dielectric Particle Systems: A Geometry-Dependent Effect.

Electrostatic interactions in systems composed of finite-sized dielectric materials extend well beyond simple point-charge approximations, particularly when many-body polarization effects become significant. This study shows that asymmetries in the size or net charge of spherical particles can trigger nontrivial phenomena, including like-charge attraction and intricate force balances involving neutral species. Through a rigorous boundary-integral framework, it is substantiated that induced surface charges propagate through iterative cascades, reflecting the full many-body, nonadditive character of polarization. Significantly, a geometry-based cutoff is adopted to discriminate whether long-range interactions can be approximated by monopoles, thereby retaining near-field multipole couplings without forfeiting computational efficiency. This approach provides significant computational gains without compromising the rigor of many-body treatment, underscoring the critical interplay between geometric factors─specifically, particle size (and its associated curvature) and interparticle separation─in determining local field intensities, which often exceed conventional Coulombic predictions. The findings can illuminate pathways for understanding and designing advanced materials and self-assembled architectures in which dielectric polarization governs or contributes to emergent behavior.