Observation of the BKT Transition in a 2D Bose Gas via Matter-Wave Interferometry

Abstract

We probe local phase fluctuations of trapped two-dimensional (2D) Bose gases using matter-wave interferometry. This enables us to measure the phase correlation function, which changes from an algebraic to an exponential decay when the system crosses the Berezinskii-Kosterlitz-Thouless (BKT) transition. We determine the temperature dependence of the BKT exponent $\eta$ and find the critical value ${\eta }_c=0.17(3)$ for our trapped system. Furthermore, we measure the local vortex density as a function of the local phase-space density, which shows a scale-invariant behaviour across the transition. Our experimental investigation is supported by Monte Carlo simulations and provides a comprehensive understanding of the BKT transition in a trapped system.

13 pages, 13 figures

References in corpus (14)

• Extension of Bogoliubov theory to quasi-condensates
• Observation of scale invariance and universality in two-dimensional Bose gases
• Superfluid behaviour of a two-dimensional Bose gas
• Observation of the Berezinskii-Kosterlitz-Thouless Phase Transition in an Ultracold Fermi Gas
• The trapped two-dimensional Bose gas: from Bose-Einstein condensation to Berezinskii-Kosterlitz-Thouless physics
• Improved detection of small atom numbers through image processing
• Critical Dynamics of a Two-dimensional Superfluid near a Non-Thermal Fixed Point
• Effects of Interactions on the Critical Temperature of a Trapped Bose Gas
• Connecting Berezinskii-Kosterlitz-Thouless and BEC phase transitions by tuning interactions in a trapped gas
• A two-dimensional quantum gas in a magnetic trap
• Prethermalization in one-dimensional Bose gases: description by a stochastic Ornstein-Uhlenbeck process
• Semiclassical theory of the quasi two-dimensional trapped Bose gas
• Probing Phase Fluctuations in a 2D Degenerate Bose Gas by Free Expansion
• Interplay of spin waves and vortices in the 2D XY model at small vortex-core energy

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• Quantum Simulations with Bilayer 2D Bose Gases in Multiple-RF-dressed Potentials
• Observation of a Bilayer Superfluid with Interlayer Coherence
• Uniaxial modulation and the Berezinskii-Kosterlitz-Thouless transition
• Measurement of total phase fluctuation in cold-atomic quantum simulators
• Detecting Phase Coherence of 2D Bose Gases via Noise Correlations
• Tilted dipolar bosons in the quasi-two-dimensional regime: From liquid stripes to droplets
• Designing Atomtronic Circuits via Superfluid Dynamics
• Simulating the Berezinskii-Kosterlitz-Thouless Transition with Complex Langevin
• A phase microscope for quantum gases
• Proposal for realizing unpaired Weyl points in a three-dimensional periodically driven optical Raman lattice
• Josephson Dynamics in 2D Ring-shaped Condensates
• CNN-Based Vortex Detection in Atomic 2D Bose Gases in the Presence of a Phononic Background
• Controlled generation of 3D vortices in driven atomic Josephson junctions