Comparing cavity and ordinary laser cooling within the Lamb-Dicke regime

TL;DR

This paper compares cavity-mediated laser cooling and ordinary laser cooling within the Lamb-Dicke regime, showing they are essentially equivalent under certain conditions and deriving key scaling laws for phonon number.

Contribution

It provides a unified analysis of cavity and ordinary laser cooling, deriving rate equations and scaling laws for the stationary phonon number in different regimes.

Findings

Cavity and ordinary laser cooling are equivalent within the Lamb-Dicke approximation.

Stationary phonon number scales as κ^2/16ν^2 in strong confinement.

Stationary phonon number scales as κ/4ν in weak confinement.

Abstract

Cavity-mediated cooling has the potential to become one of the most efficient techniques to cool molecular species down to very low temperatures. In this paper we analyse cavity cooling with single-laser driving for relatively large cavity decay rates kappa and relatively large phonon frequencies nu. It is shown that cavity cooling and ordinary laser cooling are essentially the same within the validity range of the Lamb-Dicke approximation. This is done by deriving a closed set of rate equations and calculating the corresponding stationary state phonon number and cooling rate. For example, when nu is either much larger or much smaller than kappa, the minimum stationary state phonon number scales as kappa^2/16 nu^2 (strong confinement regime) and as kappa / 4 nu (weak confinement regime), respectively.