Interisotope effects in optimal dual-isotope loading into a shallow optical trap

TL;DR

This study investigates how simultaneous loading of two rubidium isotopes into a shallow optical trap results in reduced atom numbers, attributed to inter-isotope effects disrupting laser cooling rather than collisional losses.

Contribution

It identifies inter-isotope effects as a key factor affecting dual-isotope loading efficiency in optical traps, which was previously not well understood.

Findings

Simultaneous isotope loading reduces maximum atom number compared to single isotope loading.

Homonuclear and heteronuclear collisional losses are insufficient to explain the reduction.

Inter-isotope disruptions impair laser cooling, decreasing loading rates.

Abstract

Examination of loading the isotopes $^{85}$Rb and $^{87}$Rb simultaneously into a shallow far-off-resonance trap (FORT) has revealed an unexpected decrease in maximum atom number loaded as compared to loading either isotope alone. The simultaneous loading of the FORT will be affected by additional homonuclear and heteronuclear light-assisted collisional losses. However, these losses are measured and found to be insufficient to explain the observed drop in total number of atoms loaded into the FORT. We find that our observations are consistent with a decrease in loading rate caused by inter-isotope disruptions of the efficient laser cooling required to load atoms into the optical trap.