Thesis (pdf) - Swinburne University of Technology

mirror MOT and then transferred into a current-carrying wire magnetic trap,
in which the atomic sample was further cooled by allowing the atoms with
highest kinetic energy to “evaporate” from the trap [Hes86, Mas88]. With
this cooling, the phase transition to a quantum degenerate BEC was achieved.
Then, with the current in the wires turned off, trapping of ultracold atoms
in the field of the permanent magnetic structure was successfully achieved
and these results are presented at the end of this chapter. A BEC was then
successfully realised on a similar permanent magnetic structure [Hal05, Hal06]
while the author was in Hannover working on the all-optical BEC experiment
described in Chapters 6 and 7. The measurements in this chapter were taken
together with S. Whitlock and Dr. B. Hall, and have been published in [Hal06].
Chapters 6 and 7 present the experimental set-up and the results of the
experiment at the University of Hannover, where the author participated in
the experiment for limited periods. A tri-national network grew out of this
collaboration. In Chapter 6 the set-up of the all-optical BEC experiment is
described. This apparatus was set up and first used by Dr. F. Buchkremer
for the coherence investigations in optical waveguides and traps [Buc01]. The
following experiment implemented miniaturised optical elements like arrays
of micron-sized lenses to demonstrate their in-principle use for quantum in-
formation and atom interferometry [Dum03a]. The author first joined the
experiment at that stage. An existing experimental set-up was modified and
improved, and the author was involved in experiments and measurements with
the aim of producing an all-optical BEC. This work was done together with Dr.
R. Dumke in the very beginning. Most of the changes were implemented after
Dr. Dumke had left and then optimised together with A. Lengwenus [Len04].
While the author was absent, the dipole laser system that is now used to trap
the atoms for evaporation was set up by Dr. T. Müther, J. Nes and A.-L.
Gehrmann. A description of the full apparatus can be found in their theses
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