Momentum distribution of 1D Bose gases at the quasi-condensation crossover: theoretical and experimental investigation

Abstract

We investigate the momentum distribution of weakly interacting 1D Bose gases at thermal equilibrium both experimentally and theoretically. Momentum distribution of single 1D Bose gases is measured using a focusing technique, whose resolution we improve via a guiding scheme. The momentum distribution compares very well with quantum Monte Carlo calculations for the Lieb-Liniger model at finite temperature, allowing for an accurate thermometry of the gas that agrees with (and improves upon) the thermometry based on in situ density fluctuation measurements. The quasi-condensation crossover is investigated via two different experimental parameter sets, corresponding to the two different sides of the crossover. Classical field theory is expected to correctly describe the quasi-condensation crossover of weakly interacting gases. We derive the condition of validity of the classical field theory, and find that, in typical experiments, interactions are too strong for this theory to be accurate. This is confirmed by a comparison between the classical field predictions and the numerically exact quantum Monte Carlo calculations.

8 pages

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Cited by in corpus (19)

• Ultracold atoms out of equilibrium
• Generalized Hydrodynamics in the 1D Bose gas: theory and experiments
• Extension of the Generalized Hydrodynamics to the Dimensional Crossover Regime
• Thermalisation of a trapped one-dimensional Bose gas via diffusion
• Generalised hydrodynamics with dephasing noise
• Universal contact for a Tonks-Girardeau gas at finite temperature
• Conformal field theory on top of a breathing one-dimensional gas of hard core bosons
• Matter wave Fourier optics with a strongly interacting two-dimensional Fermi gas
• Breakdown of Tan's relation in lossy one-dimensional Bose gases
• Dynamic structure factor and drag force in a one-dimensional strongly-interacting Bose gas at finite temperature
• Exact out-of-equilibrium steady states in the semiclassical limit of the interacting Bose gas
• Comparative study of one-dimensional Bose and Fermi gases with contact interactions from the viewpoint of universal relations for correlation functions
• Many-body density and coherence of trapped cold bosons
• One-particle density matrix and momentum distribution of the out-of-equilibrium 1D Tonks-Girardeau gas: Analytical results at large $N$
• Spin-incoherent one-dimensional spin-1 Bose Luttinger liquid
• Quantum corrections to the classical field approximation for one-dimensional quantum many-body systems in equilibrium
• Mesoscopic density grains in the 1d interacting Bose gas from the exact Yang-Yang solution
• One-body correlations and momentum distributions of trapped one-dimensional Bose gases at finite temperature
• Reflection phase shifts of bouncing Bogoliubov waves