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en ©2001 Gheorghe-Sorin Paraoanu Bose gas fermionic systems bosons Tunneling in Degenerate Atomic Gases Dissertation / Thesis text Leggett, Anthony J. Paraoanu, Gheorghe-Sorin 2012-06-04T17:14:02Z 2012-06-04T17:14:02Z 10000-01-01 2001 The experimental achievement of Bose-Einstein condensation in cold alkali atomic gases in 1995 has started a period of fertile research at the intersection of atomic physics, quantum optics, and condensed matter. In this thesis, various tunneling effects in both bosonic and fermionic gases are investigated. The first part of this work deals with bosons in different Josephson-type experimental setups. After a brief general introduction we establish, in Chapter 2, a mapping between the phase and the Bogoliubov representation for the Josephson oscillations; in Chapter 3 we calculate the Josephson coupling constant for the condensate in the external Josephson effect. Chapter 4 deals with Josephson effects at the level of depletion: we describe in detail the oscillatory dynamics of the virtual quasiparticles. The next Chapter is a stability analysis for the formation of vortices in the Kibble-Zurek scenario. Finally, Chapter 6 contains a discussion on the time-evolution of the many-body states in the absence of tunneling. The second part of the thesis (Chapter 7- Chapter 9) deals with fermionic systems below the BCS critical temperature. The first two of these Chapters explore the possibility of driving transitions between hyperfine states with lasers. In Chapter 7 we show that these transitions could be used to investigate the coherence of the Cooper pairs. In Chapter 8 we imagine an internal Josephson experiment which uses a pair of lasers to drive transitions between two superfluids. Finally, in Chapter 9 we examine the properties of vortices formed in trapped Cooper-paired fermionic gases. Submitted by Elizabeth Kent (eckent2@illinois.edu) on 2012-06-04T17:14:02Z No. of bitstreams: 1 2001_paraoanu.pdf: 6534523 bytes, checksum: 52166d8c59ff39525e52e31cc39207c7 (MD5) Made available in DSpace on 2012-06-04T17:14:02Z (GMT). No. of bitstreams: 1 2001_paraoanu.pdf: 6534523 bytes, checksum: 52166d8c59ff39525e52e31cc39207c7 (MD5) Previous issue date: 2001 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Elizabeth Kent (eckent2@illinois.edu) on 2012-06-04T17:14:02Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:33:16-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: thesis thesis U of I Only 4539145 http://hdl.handle.net/2142/31327 Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.