Comment on ``Coupled dynamics of atoms and radiation--pressure--driven interferometers''

TL;DR

This paper critiques previous models of atom-cavity interactions, clarifying the true steady state configuration and correcting assumptions about dipole forces and bistability in the system.

Contribution

It challenges prior assumptions by showing the actual steady state is a regular lattice and that bistability does not occur, refining the understanding of atom-cavity dynamics.

Findings

The steady state is a regular lattice, not a non-lattice configuration.

Dipole forces vanish at the true steady state, contrary to previous assumptions.

Bistability predicted earlier does not occur in this system.

Abstract

In two recent articles, Meiser and Meystre describe the coupled dynamics of a dense gas of atoms and an optical cavity pumped by a laser field. They make two important simplifying assumptions: (i) the gas of atoms forms a regular lattice and can be replaced by a fictitious mirror, and (ii) the atoms strive to minimize the dipole potential. We show that the two assumptions are inconsistent: the configuration of atoms minimizing the dipole potential is not a perfect lattice. Assumption (ii) is erroneous, as in the strong coupling regime the dipole force does not arise from the dipole potential. The real steady state, where the dipole forces vanish, is indeed a regular lattice. Furthermore, the bistability predicted by Meiser and Meystre does not occur in this system.