Theoretical and experimental studies on ultra-cold atoms in optical traps

• Main Author: Deb, Amita
• Published: University of Oxford 2009
• Subjects: 539.7
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.600174

This thesis describes a number of theoretical and experimental studies on the production, manipulation and detection of ultra-cold atoms in arrays of optical traps, i. e. optical lattices for applications such as direct quantum simulation of many-body systems and quantum information processing. A method of deterministically preparing a single atom in each site of an optical lattice is explored and the parameter regime that would be required to implement this protocol in experiments is investigated. A novel method of state-selective spatial transfer of atoms between neighbouring sites of a lattice using an intermediate trap is reported and the experimental parameters worked out. The theory of off-resonant light scattering from atoms in an optical lattice is explored. The possibility of using the far- field intensity distribution and t he frequency spectrum of the light scattered from atoms in an optical lattice for performing thermometry of atoms and for identifying quantum fluctuations in the system are investigated for cases of non-interacting fermions and weakly-interacting bosons. A spatial filtering method for detecting a small number of classical defects in an optical lattice is investigated. Experiments on trapping and manipulating Bose-Einstein condensates (BEC) of 8 1Rb atoms in dynamically configurable t raps created using spatial light modulators are discussed. The construction of a new magnetic trap for trapping and magnetically transporting atoms and the experimental stages subsequently leading to the production of BECs are reported.