Negative scattering asymmetry parameter for dipolar particles: Unusual reduction of the transport mean free path and radiation pressure

TL;DR

This paper predicts negative scattering asymmetry parameters in dipolar particles, leading to a reduction in the transport mean free path below the scattering mean free path, with implications for light transport in complex media.

Contribution

It establishes a theoretical relationship between dipolar interactions, scattering asymmetry, and transport properties, revealing conditions for negative asymmetry parameters in magnetodielectric particles.

Findings

Negative g can minimize the transport mean free path.

Transport mean free path can be below the scattering mean free path.

Applicable to particles satisfying Kerker conditions.

Abstract

We establish a relationship between the electric magnetic dipole interaction force from a plane wave on a small magnetodielectric particle, the transport cross-section and the scattering asymmetry parameter, g. In this way, we predict negative g that minimize the transport mean free-path below values of the scattering mean free path of a dilute suspension of both perfectly reflecting spheres as well as of those that satisfy the so-called Kerker conditions, like high permittivity dielectric ones.