Towards solitons in a 2D BEC apparatus

O’Neale, Charlotte Alicia Susan (2015). Towards solitons in a 2D BEC apparatus. University of Birmingham. Ph.D.

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Abstract

This thesis presents work towards the realisation of dark solitons in a two-dimensional Bose-Einstein condensate.
The technical redesign of two sets of coils, necessary for magnetic trapping of the atom cloud in order to
create a condensate, is reported. Two different types of coil technology are presented, discussed, and used.
The fabrication of the coils is described, and each set of coils is characterised. Both sets of coils have been installed on the main experiment and are fully operational.
A key aspect of this thesis is the development of an optical system capable of achieving resolution on the micrometer scale, which can be used for manipulation of a two-dimensional condensate by the method of phase imprinting. The optical system demagnifes the image on a spatial light modulator and focuses the image on the atom plane. Characterisation of the resolution of the optical system shows that a resolution of 3 µm is achieved. The optical system has successfully been implemented on the main experiment and has been used to manipulate the condensate.
A two-dimensional BEC of \(^{87}\)Rb with 31000 atoms and a temperature of 88 nK is realised in a dipole trap of frequencies ω\(_x\) = 2π∙5.8 Hz, ω\(_y\)= 2π∙19.1 Hz, ω\(_z\)= 2π∙269.4 Hz, with gravity being in the z-direction. The method of phase imprinting is used to create the first observed soliton in a 2D BEC. Preliminary analysis of the soliton velocity, width and curvature is presented.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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