P. E. S. Tavares

Quantum turbulence in trapped atomic Bose–Einstein condensates

Turbulence, the complicated fluid behavior of nonlinear and statistical nature, arises in many physical systems across various disciplines, from tiny laboratory scales to geophysical and astrophysical ones. The notion of turbulence in the quantum world was conceived long ago by Onsager and Feynman, but the occurrence of turbulence in ultracold gases has been studied in the laboratory only very recently. Albeit new as a field, it already offers new paths and perspectives on the problem of turbulence. Herein we review the general properties of quantum gases at ultralow temperatures paying particular attention to vortices, their dynamics and turbulent behavior. We review the recent advances both from theory and experiment. We highlight, moreover, the difficulties of identifying and characterizing turbulence in gaseous Bose-Einstein condensates compared to ordinary turbulence and turbulence in superfluid liquid helium and spotlight future possible directions.

Out-of-phase oscillation between superfluid and thermal components for a trapped Bose condensate under oscillatory excitation

The vortex nucleation and the emergence of quantum turbulence induced by oscillating magnetic fields, introduced by [1, 2], left a few open questions concerning the basic mechanisms causing those interesting phenomema. Here, we report the experimental observation of the slosh dynamics of a magnetically trapped

Nonlinear Dependence Observed in Quadrupolar Collective Excitation of a Trapped BEC

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Investigation of the Momentum Distribution of an Excited BEC by Free Expansion: Coupling with Collective Modes

Rb Bose-Einstein condensate (BEC) under the influence of a time-varying magnetic field. We observed a clear relative displacement in between the condensed and the thermal fraction center-of-mass. We have identified this relative counter move as an out-of-phase oscillation mode, which is able to produce ripples on the condensed/thermal fractions interface. The out-of-phase mode provides good evidences of a mechanism involved in the vortex nucleation and evolution when excited by time dependent magnetic fields.The vortex nucleation and the emergence of quantum turbulence induced by oscillating magnetic fields, introduced by Henn E A L, et al. 2009 (Phys. Rev. A 79, 043619) and Henn E A L, et al. 2009 (Phys. Rev. Lett. 103, 045301), left a few open questions concerning the basic mechanisms causing those interesting phenomena. Here, we report the experimental observation of the slosh dynamics of a magnetically trapped

Matter wave speckle observed in an out-of-equilibrium quantum fluid

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Characteristics and Perspectives of Quantum Turbulence in Atomic Bose-Einstein Condensates

Rb Bose-Einstein condensate (BEC) under the influence of a time-varying magnetic field. We observed a clear relative displacement in between the condensed and the thermal fraction center-of-mass. We have identified this relative counter move as an out-of-phase oscillation mode, which is able to produce ripples on the condensed/thermal fractions interface. The out-of-phase mode can be included as a possible mechanism involved in the vortex nucleation and further evolution when excited by time dependent magnetic fields.

Twisted unwinding of multi-charged quantum vortex and generation of turbulence in atomic Bose-Einstein condensates

We report the experimental observation of the collective excitations induced in a magnetically trapped

Chaotic nature of turbulent Bose-Einstein condensates

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