Dispersion Interaction Between Thin Conducting Cylinders

TL;DR

This paper investigates the long-range dispersion interactions between elongated conducting molecules, extending existing theories to excited states, and predicts a slow decay rate of energy transfer due to unique distance dependencies.

Contribution

It extends the theory of dispersion interactions to excited states for conducting molecules, revealing a long-range interaction with a distinctive $f(R)/R^2$ dependence.

Findings

Interaction energy decays as $f(R)/R^2$ at long range

Long-range interactions are stronger than in nonconducting molecules

Energy transfer between conducting molecules decays slowly over distance

Abstract

The ground state and excited state resonance dipole-dipole interaction energy between two elongated conducting molecules are explored. We review the current status for ground state interactions. This interaction is found to be of a much longer range than in the case when the molecules are pointlike and nonconducting. These are well known results found earlier by Davies, Ninham, and Richmond, and later, using a different formalism, by Rubio and co-workers. We show how the theory can be extended to excited state interactions. A characteristic property following from our calculation is that the interaction energy dependence with separation ($R$) goes like $f(R)/R^2$ both for resonance and for the van der Waals case in the long range limit. In some limits $f(R)$ has a logarithmic dependency and in others it takes constant values. We predict an unusual slow decay rate for the energy transfer between conducting molecules.