Rubidium-87 Bose-Einstein condensate in an optically plugged quadrupole trap

TL;DR

This paper reports on creating Bose-Einstein condensates of Rubidium-87 in an optically plugged magnetic quadrupole trap, combining experimental and theoretical analysis to optimize evaporation and trap stability.

Contribution

It introduces a detailed study of the trapping potential and measurement methods, enabling reliable production of degenerate gases in a hybrid trap.

Findings

Successful production of 87Rb Bose-Einstein condensates in the hybrid trap.

Validated theoretical model of the trapping potential.

Established measurement techniques for trap frequencies.

Abstract

We describe an experiment to produce 87Rb Bose-Einstein condensates in an optically plugged magnetic quadrupole trap, using a blue-detuned laser. Due to the large detuning of the plug laser with respect to the atomic transition, the evaporation has to be carefully optimized in order to efficiently overcome the Majorana losses. We provide a complete theoretical and experimental study of the trapping potential at low temperatures and show that this simple model describes well our data. In particular we demonstrate methods to reliably measure the trap oscillation frequencies and the bottom frequency, based on periodic excitation of the trapping potential and on radio-frequency spectroscopy, respectively. We show that this hybrid trap can be operated in a well controlled regime that allows a reliable production of degenerate gases.