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dc.contributor.advisorRaman, Chandra
dc.contributor.authorVinit, Anshuman
dc.date.accessioned2016-08-22T12:23:18Z
dc.date.available2016-08-22T12:23:18Z
dc.date.created2016-08
dc.date.issued2016-08-03
dc.date.submittedAugust 2016
dc.identifier.urihttp://hdl.handle.net/1853/55621
dc.description.abstractThis thesis discusses non-equilibrium phenomena in antiferromagnetic spinor quantum gases. We investigate, both experimentally and theoretically, the quench dynamics of antiferromagnetic spinor Bose-Einstein condensates in the vicinity of a zero temperature quantum phase transition. A microwave dressing field was used as a novel tool to access the polar to antiferrmagnetic quantum phase transition at the quadratic Zeeman shift, q=0. By performing instantaneous quenches across the phase transition,a dynamical instability was induced in the atomic cloud. This lead to pair formation and rapid amplification of spin +/-1 atoms through spin-mixing collisions. The spatial ordering kinetics in the vicinity of the phase transition was quantified by performing the local spin measurement. The coarsening dynamics was observed for the instability for q < 0, as it nucleated small domains that grew to the axial size of the cloud. Rich nonequilibrium behavior was observed in the form of growth and decay of both nematic and magnetic spin waves, following the quench. The spatiotemporal evolution was characterized through two particle correlations between atoms in each pair of spin states, which revealed dramatic differences between the dynamics of the spin correlations and those of the spin populations. Finally, we demonstrate the remarkable influence of linear Zeeman term on non-equilibrium dynamics of spinor Bose-Einstein condensates. We show that contrary to prior understanding magnetic field gradient actually suppresses the tendency of spin 0 state to separate into spin +/-1 state. This reconciles the Bogoliubov discrepancies and leads to a dramatic sharpening of the transition point, resulting in a resolution at the 1 Hz level. Our results point to the use of dynamics, rather than equilibrium quantities for high precision measurements of phase transitions in quantum gases.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherGeorgia Institute of Technology
dc.subjectSpinor
dc.subjectBose-Einstein condensate
dc.titleInvestigating non-equilibrium phenomena in spinor antiferromagnetic Bose-Einstein condensates
dc.typeDissertation
dc.description.degreePh.D.
dc.contributor.departmentPhysics
thesis.degree.levelDoctoral
dc.contributor.committeeMemberChapman, Michael
dc.contributor.committeeMemberTrebino, Rick
dc.contributor.committeeMemberFirst, Philip
dc.contributor.committeeMemberAmini, Jason
dc.date.updated2016-08-22T12:23:19Z


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