Thesis (pdf) - Swinburne University of Technology

Abstract
Interferometry with atoms is a young discipline of physics. The first interfer-
ometers were realised in the early 1990s, using light pulses as beamsplitters
in momentum space. Recent developments in atom optics have led to new
proposals for interferometers, where the splitting takes place spatially. Mag-
netic and optical traps are both suited for this kind of interferometer if a well
defined and highly controllable trap is realised. In this thesis results from two
experiments that in principle allow the creation of such traps are presented.
After reviewing the principles and techniques of atom optics necessary for
the understanding of this thesis, a theoretical discussion about the spatial
single atom interferometer in a double well potential follows. It is shown that
within reasonable limits the system can be reduced to two levels and solved
by the Bloch equations. Using the realistic case of a not perfectly symmetric
double well potential allows an understanding of the physics behind such an
interferometer: how phase is accumulated and how localisation of the atoms
leads to the loss of the interferometric signal.
Then two experiments are presented. One experiment was newly built up as
part of this thesis: it uses a novel hybrid “atom chip” with a combination of a
magneto-optical film and current-carrying structures to produce the magnetic
trapping potentials. This experiment allowed 5·10 8 87 Rb atoms to be captured
in a magneto-optical trap, where the atom-chip’s surface acts as a mirror. The
atoms were then transferred into a purely magnetic trap which was created by
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