Optical Confinement of a Bose-Einstein Condensate

TL;DR

This paper demonstrates the optical confinement of a Bose-Einstein condensate of sodium atoms using a focused infrared laser, enabling studies beyond magnetic traps and measuring decay rates at high densities.

Contribution

It introduces a method for confining Bose-Einstein condensates optically with high atom numbers and densities, expanding experimental possibilities beyond magnetic traps.

Findings

Confined over five million sodium atoms in an optical trap.

Measured three-body decay rate constant for sodium condensates.

Achieved lifetimes exceeding 10 seconds at lower densities.

Abstract

Bose-Einstein condensates of sodium atoms have been confined in an optical dipole trap using a single focused infrared laser beam. This eliminates the restrictions of magnetic traps for further studies of atom lasers and Bose-Einstein condensates. More than five million condensed atoms were transferred into the optical trap. Densities of up to $3 \times 10^{15} cm^{-3}$ of Bose condensed atoms were obtained, allowing for a measurement of the three-body decay rate constant for sodium condensates as $K_3 = (1.1 \pm 0.3) \times 10^{-30} cm^6 s^{-1}$. At lower densities, the observed 1/e lifetime was more than 10 sec. Simultaneous confinement of Bose-Einstein condensates in several hyperfine states was demonstrated.