Characteristics of unconventional Rb magneto-optical traps

TL;DR

This paper explores various unconventional magneto-optical traps for rubidium-87 using type-II transitions, revealing diverse behaviors, lifetimes, and temperatures, and providing insights into their formation conditions and collision dynamics.

Contribution

It introduces new MOT configurations using type-II transitions with detailed characterization of their properties and formation conditions, expanding the understanding of unconventional trapping methods.

Findings

Lifetimes range from 0.1 to 15 seconds.

Temperature differences up to three orders of magnitude between red- and blue-detuned MOTs.

Large ring-like structures with no central density observed.

Abstract

We study several new magneto-optical trapping configurations in $^{87}$Rb. These unconventional MOTs all use type-II transitions, where the angular momentum of the ground state is greater than or equal to that of the excited state, and they may use either red-detuned or blue-detuned light. We describe the conditions under which each new MOT forms. The various MOTs exhibit an enormous range of lifetimes, temperatures and density distributions. At the detunings where they are maximized, the lifetimes of the various MOTs vary from 0.1 to 15 s. One MOT forms large ring-like structures with no density at the centre. The temperature in the red-detuned MOTs can be three orders of magnitude higher than in the blue-detuned MOTs. We present measurements of the capture velocity of a blue-detuned MOT, and we study how the loss rate due to ultracold collisions depends on laser intensity and detuning.