Long-range Self-assembly via the Mutual Lorentz Force of Plasmon Radiation

TL;DR

This paper uncovers a novel long-range self-assembly mechanism driven by the Lorentz force from plasmon radiation, enabling the formation of aligned nanoparticle structures beyond near-field interactions.

Contribution

It introduces a new physical mechanism for particle self-assembly based on the Lorentz force from plasmon radiation, distinct from traditional short-range interactions.

Findings

Linearly-polarized light induces 80-nm Au nanoparticle alignment.

Self-assembly occurs above a critical light intensity and concentration.

Nanostructures formed are significantly longer than plasmon near-field scales.

Abstract

Long-range interactions often proceed as a sequence of hopping through intermediate, statistically-favored events. Here, we identify a widely-overlooked mechanism for the mechanical motion of particles that arises from the Lorentz force and plasmon radiation. Even if the radiation is weak, the nonconservative Lorentz force produces stable locations perpendicular to the plasmon oscillation; over time, distinct patterns emerge. Experimentally, linearly-polarized light leads to the formation of 80-nm Au nanoparticles, perpendicularly-aligned, with lengths that are orders of magnitude greater than their plasmon near-field interaction. There is a critical intensity threshold and optimal concentration for observing self-assembly.