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Gauge matters: Observing the vortex-nucleation transition in a Bose condensate



Ian B. Spielman, LeBlanc Lindsey, Karina Jimenez-Garcia, Ross Williams, Matthew Beeler, William D. Phillips


The order parameter of a quantum-coherent many-body system includes one or more phase degrees of freedom, which, owing to the phase information's relationship to velocity, can be accessed using time-of-flight (TOF) imaging. Here, trapped Bose-Einstein condensates (BECs) equilibrated in Raman-induced artificial magnetic fields exhibited a shearing motion during field-free TOF. This shearing, initiated by the artificial electric field accompanying the magnetic field's turn-off, suddenly increased at magnetic fields sufficient to nucleate vortices in the superfluid BEC. By comparing to superfluid hydrodynamic calculations and Gross-Pitaevskii numerics, we confirmed the location and nature of this structural phase transition from the vortex-free state. The shear-inducing electric field was generated by a changing vector potential, which depends on the details of the apparatus with which the artificial magnetic field was created. Measurements of this kind offer opportunities for studying phase degrees of freedom in unconventional systems.
Physical Review Letters


artificial gauge fields, Bose-Einstein Condensation, ultracold atoms, vortices


Spielman, I. , Lindsey, L. , Jimenez-Garcia, K. , Williams, R. , Beeler, M. and Phillips, W. (2015), Gauge matters: Observing the vortex-nucleation transition in a Bose condensate, Physical Review Letters, [online], (Accessed February 28, 2024)
Created June 18, 2015, Updated November 10, 2018