Observation of pair condensation in the quasi-2D BEC-BCS crossover

Abstract

The condensation of fermion pairs lies at the heart of superfluidity. However, for strongly correlated systems with reduced dimensionality the mechanisms of pairing and condensation are still not fully understood. In our experiment we use ultracold atoms as a generic model system to study the phase transition from a normal to a condensed phase in a strongly interacting quasi-two-dimensional Fermi gas. Using a novel method, we obtain the in situ pair momentum distribution of the strongly interacting system and observe the emergence of a low-momentum condensate at low temperatures. By tuning temperature and interaction strength we map out the phase diagram of the quasi-2D BEC-BCS crossover.

References in corpus (40)

• Many-Body Physics with Ultracold Gases
• Observation of resonance condensation of fermionic atom pairs
• Condensation of Pairs of Fermionic Atoms Near a Feshbach Resonance
• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Berezinskii-Kosterlitz-Thouless Crossover in a Trapped Atomic Gas
• Experimental Study of the BEC-BCS Crossover Region in Lithium 6
• Large momentum part of fermions with large scattering length
• Collective excitations of a degenerate gas at the BEC-BCS crossover
• Bose-Einstein condensation in quasi2D trapped gases
• Attractive and repulsive Fermi polarons in two dimensions
• Interatomic collisions in a tightly confined Bose gas
• The Challenge of Unconventional Superconductivity
• Observation of scale invariance and universality in two-dimensional Bose gases
• Yang-Yang thermodynamics on an atom chip
• Critical Point of a Weakly Interacting Two-Dimensional Bose Gas
• Precise characterization of ^6Li Feshbach resonances using trap-sideband resolved RF spectroscopy of weakly bound molecules
• Observation of a pairing pseudogap in a two-dimensional Fermi gas
• Observation of a 2D Bose-gas: from thermal to quasi-condensate to superfluid
• Radiofrequency spectroscopy of a strongly interacting two-dimensional Fermi gas
• Strong saturation absorption imaging of dense clouds of ultracold atoms
• Superfluid behaviour of a two-dimensional Bose gas
• Observation of a two-dimensional Fermi gas of atoms
• Two-Dimensional Weakly Interacting Bose Gas in the Fluctuation Region
• Evolution of Fermion Pairing from Three to Two Dimensions
• BCS-BEC crossover in a two-dimensional Fermi gas
• Exploring the thermodynamics of a two-dimensional Bose gas
• Crossover from 2D to 3D in a weakly interacting Fermi gas
• Superfluid transition in quasi2D Fermi gases
• Ground-state pressure of quasi-2D Fermi and Bose gases
• Bose-Einstein condensation into non-equilibrium states studied by condensate focusing
• Observation of the Presuperfluid Regime in a Two-Dimensional Bose Gas
• Improved detection of small atom numbers through image processing
• Universal equation of state and pseudogap in the two-dimensional Fermi gas
• Quasicondensation and coherence in the quasi-two-dimensional trapped Bose gas
• Matter wave Fourier optics with a strongly interacting two-dimensional Fermi gas
• Pair Correlations in the Two-Dimensional Fermi Gas
• Coherence properties of a 2D trapped Bose gas around the superfluid transition
• Evolution from BCS to BKT superfluidity in one-dimensional optical lattices
• Quasi-two-dimensional Fermi gases at finite temperature
• Pseudogap phenomena in a two-dimensional ultracold Fermi gas near the Berezinskii-Kosterlitz-Thouless transition

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• High temperature pairing in a strongly interacting two-dimensional Fermi gas
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• Calibrating High Intensity Absorption Imaging of Ultracold Atoms
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• Superconductivity induced by strong electron-exciton coupling in doped atomically thin semiconductor heterostructures
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• Effective theory for ultracold strongly interacting fermionic atoms in two dimensions
• Enhancing $T_{\mathrm{c}}$ in a composite superconductor/metal bilayer system: a dynamical cluster approximation study
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• Universal Properties of Fermi Gases in One-dimension
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