Probing Phase Fluctuations in a 2D Degenerate Bose Gas by Free Expansion
arXiv:1206.2232 · doi:10.1103/PhysRevLett.109.125301
Abstract
We measure the power spectrum of the density distribution of a freely expanding 2D degenerate Bose gas, where irregular density modulations gradually develop due to the initial phase fluctuations in the sample. The spectrum has an oscillatory shape, where the peak positions are found to be independent of temperature and show scaling behavior in the course of expansion. The relative intensity of phase fluctuations is estimated from the normalized spectral peak strength and observed to decrease at lower temperatures, confirming the thermal nature of the phase fluctuations. We investigate the relaxation dynamics of nonequilibrium states using the power spectrum. Free vortices are observed with ring-shaped density ripples in a perturbed sample after a long relaxation time.
arXiv comment5 pages, 4 figures
References in corpus (18)
- Berezinskii-Kosterlitz-Thouless Crossover in a Trapped Atomic Gas
- Spontaneous symmetry breaking in a quenched ferromagnetic spinor Bose condensate
- Non-equilibrium coherence dynamics in one-dimensional Bose gases
- Observation of vortex dipoles in an oblate Bose-Einstein condensate
- Observation of Phase Fluctuations in Bose-Einstein Condensates
- Observation of scale invariance and universality in two-dimensional Bose gases
- Observation of a 2D Bose-gas: from thermal to quasi-condensate to superfluid
- Observation of Topologically Stable 2D Skyrmions in an Antiferromagnetic Spinor Bose-Einstein Condensate
- Exploring the thermodynamics of a two-dimensional Bose gas
- Critical Point of an Interacting Two-Dimensional Atomic Bose Gas
- Observation of the Presuperfluid Regime in a Two-Dimensional Bose Gas
- Two-point density correlations of quasicondensates in free expansion
- The trapped two-dimensional Bose gas: from Bose-Einstein condensation to Berezinskii-Kosterlitz-Thouless physics
- Breakdown of Scaling in the Nonequilibrium Critical Dynamics of the Two-Dimensional XY Model
- Suppression of Kelvon-induced decay of quantized vortices in oblate Bose-Einstein Condensates
- Coherence properties of a 2D trapped Bose gas around the superfluid transition
- Semiclassical theory of the quasi two-dimensional trapped Bose gas
- Fast production of large 23Na Bose-Einstein condensates in an optically plugged magnetic quadrupole trap
Cited by in corpus (19)
- Relaxation of superfluid turbulence in highly oblate Bose-Einstein condensates
- Half-Quantum Vortices in an Antiferromagnetic Spinor Bose-Einstein Condensate
- Connecting Berezinskii-Kosterlitz-Thouless and BEC phase transitions by tuning interactions in a trapped gas
- Observation of Thermally Activated Vortex Pairs in a Quasi-2D Bose Gas
- Observation of the BKT Transition in a 2D Bose Gas via Matter-Wave Interferometry
- Superfluidity and relaxation dynamics of a laser-stirred 2D Bose gas
- Probing superfluidity in a quasi two-dimensional Bose gas through its local dynamics
- Signatures of a universal jump in the superfluid density in two-dimensional Bose gas with finite number of particles
- Optimally focused cold atom systems obtained using density-density correlations
- Spin-driven stationary turbulence in spinor Bose-Einstein condensates
- Free expansion of quasi-2D Bose-Einstein condensates with quantized vortices
- Scaling behavior of density fluctuations in an expanding quasi-2D degenerate Bose gas
- Noise correlations of two-dimensional Bose gases
- A Non-Gaussian Variational Approach to Fermi Polarons in One- and Two-dimensional Lattices
- Detecting Phase Coherence of 2D Bose Gases via Noise Correlations
- Optimizing the optical imaging system by \emph{in-situ} imaging the plugged hole in the ultracold atoms
- CNN-Based Vortex Detection in Atomic 2D Bose Gases in the Presence of a Phononic Background
- Observation of the universal jump across the Berezinskii-Kosterlitz-Thouless transition in two-dimensional Bose gases
- Vortex Operator and BKT Transition in Abelian Duality