Return to search

Schrodinger, Dirac and beyond : non-Abelian gauge fields in ultracold quantum gases

In this thesis, optically induced non-Abelian gauge fields in ultracold atoms are investigated. Gauge fields can emerge in the equation of motion for the optically addressed ultracold atoms. To this end, spacially dependent dark states are necessary for the internal states of the atoms. A tripod level scheme yields two degenerate dark states which leads to a non-Abelian SU(2) gauge field. These fields can be understood in terms of spin-orbit coupling between the momentum of the atom and its internal pseudo-spin formed by the dark state manifold. On a ring trap, this spin-orbit coupling leads to internal and spacial Josephson oscillations, persistent currents and grey solitons. The influence of interatomic interactions is crucial for solitons and leads to modifications of the groundstate in a harmonically trapped scenario. Similarities between ultracold atoms and high energy physics are drawn in the low momentum limit as the dispersion relation offers a widely controllable Dirac cone there. With an induced mass gap Zitterbewegung and bright solitons are investigated. Moreover, non-linear Dirac equations, adapted from high energy physics, lead to new self confining solutions for ultracold gases. Further analogues between ultracold atoms and quantum chromodynamics, like chiral symmetry breaking are discussed

Identiferoai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:527387
Date January 2010
CreatorsMerkl, Michael
ContributorsOhberg, Patrik
PublisherHeriot-Watt University
Source SetsEthos UK
Detected LanguageEnglish
TypeElectronic Thesis or Dissertation
Sourcehttp://hdl.handle.net/10399/2329

Page generated in 0.0016 seconds