Spontaneous atomic crystallization via diffractive dephasing in optical cavities

TL;DR

This paper discusses an experiment demonstrating spontaneous atomic crystallization into a hexagonal phase within an optical cavity, mediated by diffractive dephasing and observable with moderate finesse cavities.

Contribution

It introduces a novel experimental setup for observing spontaneous atomic crystallization driven by diffractive dephasing in a multi-mode optical cavity.

Findings

Spontaneous formation of hexagonal atomic structures observed.

The transition is feasible with moderate finesse cavities.

A new anti-reflected cell design supports the experiment.

Abstract

The design of an experiment on the spontaneous crystallization of a laser-cooled, but thermal atomic cloud into a hexagonally structured phase is discussed. Atomic interaction is mediated by the dipole potential of an optical lattice formed spontaneously in a multi-mode degenerate cavity from single-mode longitudinal pumping. The length scale of the structure is given by the diffractive dephasing between the spontaneous sidebands and the on-axis pump. A linear stability indicates that the transition can be observed in a cavity of moderate finesse compatible with having the cavity mirrors outside the vacuum cell. A new anti-reflected cell has been assembled for this purpose.