Calibrating the momentum width of a trapped Bose-Einstein condensate by one-dimensional optical lattice pulse sequences

Abstract

We experimentally measured the ultra-narrow momentum width of an optical trapped Bose-Einstein condensate (BEC) in situ based on matter-wave interference, which validates our previous theoretical work [arXiv: 2205.02416]. By sweeping the interval of double stand-wave pulses, the BEC wave packet was splitted into different diffraction orders and then we counted the oscillation curve of the population of zero-momentum state to calibrate the momentum width. Compared with our simplified theory, we observed an accelerated evolution of interference fringes in time-domain. We evaluated this interference process minutely by numerically calculating the Gross-Pitaevskii equation and using Wigner function to intuitively demonstrate the influence of the external potential and nonlinear term. We confirmed that the reduction of interference fringe evolution period actually originates from the synergistic cooperation of the mean-field interaction of the BEC and spatial density modulation caused by the interference between different momentum states. Our approach could be generalized to other ultra-cold atomic gases with different momentum distributions, and in principle a single shot can obtain the result. This quantum thermometry is particularly suitable for momentum width calibration in practical deep cooling experiments, while for atomic samples at pK level the mean-field interaction can be safely ignored.

arXiv comment12 pages, 7 figures

References in corpus (26)

• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Quantum Simulation
• Models of Wave-function Collapse, Underlying Theories, and Experimental Tests
• Bragg spectroscopy of a Bose-Einstein condensate
• Precision Measurement of the Newtonian Gravitational Constant Using Cold Atoms
• Ground-State Properties of Magnetically Trapped Bose-Condensed Rubidium Gas
• Observation of quantum Hawking radiation and its entanglement in an analogue black hole
• Gravitational wave detection with optical lattice atomic clocks
• An Atom Michelson Interferometer on a Chip Using a Bose-Einstein Condensate
• Matter wave lensing to picokelvin temperatures
• Macroscopicity of Mechanical Quantum Superposition States
• Why momentum width matters for atom interferometry with Bragg pulses
• Atom interferometric gravitational wave detection using heterodyne laser links
• High efficiency symmetric beam splitter for cold atoms with a standing wave light pulse sequence
• Quantum Test of the Equivalence Principle and Space-Time aboard the International Space Station
• Experimental demonstration of remotely creating Wigner negativity via quantum steering
• A space-based quantum gas laboratory at picokelvin energy scales
• Observation of a dynamical sliding phase superfluid with P-band bosons
• Accurate Determination of Hubble Attenuation and Amplification in Expanding and Contracting Cold-Atom Universes
• Spatial and Temporal Coherence in Strongly Coupled Plasmonic Bose-Einstein Condensates
• Explicit Solution of the Time Evolution of the Wigner Function
• Spin-conservation propensity rule for three-body recombination of ultracold Rb atoms
• The Emergency of Pico-Kelvin Physics
• Bragg spectroscopy and Ramsey interferometry with an ultracold Fermi gas
• Velocimetry of cold atoms by matterwave interferometry
• Characterizing ultra-narrow momentum of atoms by standing-wave light-pulse sequences