Collective behavior of oscillating electric dipoles

TL;DR

This study investigates the collective dynamics of randomly oriented oscillating electric dipoles with a $1/r^3$ interaction, revealing how molecular concentration affects spectral properties and proposing a spectroscopic method to detect electrodynamic interactions relevant to biology.

Contribution

It introduces a model of biomolecular dipoles with $1/r^3$ coupling, analyzing how their collective behavior varies with concentration and suggesting experimental detection strategies.

Findings

Spectral changes correlate with intermolecular distance.

Proposed spectroscopic approach to detect electrodynamic interactions.

Potential relevance of these interactions to biological systems.

Abstract

The present work reports about the dynamics of a collection of randomly distributed, and randomly oriented, oscillators in 3D space, coupled by an interaction potential falling as $1/r^3$, where r stands for the inter-particle distance. This model schematically represents a collection of identical biomolecules, coherently vibrating at some common frequency, coupled with a $1/r^3$ potential stemming from the electrodynamic interaction between oscillating dipoles. The oscillating dipole moment of each molecule being a direct consequence of its coherent (collective) vibration. By changing the average distance among the molecules, neat and substantial changes in the power spectrum of the time variation of a collective observable are found. As the average intermolecular distance can be varied by changing the concentration of the solvated molecules, and as the collective variable investigated is proportional to the projection of the total dipole moment of the model biomolecules on a coordinate plane, we have found a prospective experimental strategy of spectroscopic kind to check whether the mentioned intermolecular electrodynamic interactions can be strong enough to be detectable, and thus to be of possible relevance to biology.