Magnetic trapping of a cold Rb-Cs atomic mixture

TL;DR

This paper describes an apparatus for trapping and studying ultracold mixtures of rubidium and cesium atoms, including measurements of interspecies loss rates and a novel technique to improve atom loading efficiency into magnetic traps.

Contribution

It introduces a new method for reducing interspecies loss in ultracold atomic mixtures by spatially separating the clouds, enhancing magnetic trap loading.

Findings

Measured interspecies trap loss rate coefficients beta_RbCs and beta_CsRb.

Demonstrated a technique to spatially separate atom clouds to reduce losses.

Achieved improved loading of atoms into magnetic traps.

Abstract

We present an apparatus for the study of an ultracold gaseous atomic mixture of 133Cs and 87Rb. The mixture is prepared using a double magneto-optical trap (MOT) system in which a two-species pyramid MOT acts as a source of cold atoms for a `science' MOT. Measurements of the interspecies trap loss rate coefficients beta_RbCs and beta_CsRb in the science MOT are reported. After the initial MOT phase, atoms in the mixture are optically pumped into the magnetically trappable |F=3,m_F=-3> and |F=1,m_F=-1> states of Cs and Rb (respectively) and loaded into an Ioffe-Pritchard magnetic trap. We demonstrate a novel technique for limiting the interspecies loss rate in the science MOT by spatially separating the two trapped atom clouds, which greatly enhances the number of atoms which can be loaded into the magnetic trap.