Experiments with Atomic and Molecular Quantum Gas Microscopes

In some recent experiments an ultracold gas of $^{40}$ K $_2$ (or $^{6}$ Li $_2$ ) molecules has been produced from a degenerate two-component Fermi gas of $^{40}$ K (or $^{6}$ Li) atoms by adiabatic passage through a Feshbach resonance. The maximum atom-molecule transfer efficiency is reported to be about 50%. We propose a simple microscopic model to characterize the ground state of the gas in the vicinity of the resonance, and show that the term describing the atom-molecule coupling is responsible for the observed efficiency 50%. Our result also suggests that the experiments have produced a molecular condensate.In some recent experiments an ultracold gas of $^{40}$K$_2$ (or $^{6}$Li$_2$) molecules has been produced from a degenerate two-component Fermi gas of $^{40}$K (or $^{6}$Li) atoms by adiabatic passage through a Feshbach resonance. The maximum atom-molecule transfer efficiency is reported to be about 50%. We propose a simple microscopic model to characterize the ground state of the gas in the vicinity of the resonance, and show that the term describing the atom-molecule coupling is responsible for the observed efficiency 50%. Our result also suggests that the experiments have produced a molecular condensate.

arXiv:cond-mat/0308474Aug 24, 20030 citations

Quantum gas microscope

Jonathon I. Gillen, Waseem Bakr, Amy Peng +2 more

Bulletin of the American Physical SocietyMar 19, 20091 citation

Microscopic theory of atom-molecule oscillations in a Bose-Einstein condensate

Thorsten Köhler, Thomas Gasenzer, Keith R. Burnett

In a recent experiment at JILA [E. A. Donley et al., Nature (London) 417, 529 (2002)] an initially pure condensate of ${}^{85}\mathrm{Rb}$ atoms was exposed to a specially designed time-dependent magnetic-field pulse in the vicinity of a Feshbach resonance. The production of additional components of the gas as well as their oscillatory behavior have been reported. We apply a microscopic theory of the gas to identify these components and determine their physical properties. Our time-dependent studies allow us to explain the observed dynamic evolution of all fractions, and to identify the physical relevance of the pulse shape. Based on ab initio predictions, our theory strongly supports the view that the experiments have produced a molecular condensate.In a recent experiment at JILA [E. A. Donley et al., Nature (London) 417, 529 (2002)] an initially pure condensate of ${}^{85}\mathrm{Rb}$ atoms was exposed to a specially designed time-dependent magnetic-field pulse in the vicinity of a Feshbach resonance. The production of additional components of the gas as well as their oscillatory behavior have been reported. We apply a microscopic theory of the gas to identify these components and determine their physical properties. Our time-dependent studies allow us to explain the observed dynamic evolution of all fractions, and to identify the physical relevance of the pulse shape. Based on ab initio predictions, our theory strongly supports the view that the experiments have produced a molecular condensate.

arXiv:cond-mat/0209100Physical Review AJan 7, 200398 citations

Progress Towards a Quantum Gas Microscope

Amy Peng, Waseem Bakr, Jonathon I. Gillen +2 more

Bulletin of the American Physical SocietyMay 28, 20080 citations

Collisional Microscopy of Quantum Gases

Qi Liu, Craig Price, Nathan Gemelke

Bulletin of the American Physical SocietyJun 10, 20150 citations

Microscopic electronic structure tomography of Rydberg macrodimers

Simon Hollerith, Jun Rui, Antonio Rubio-Abadal +5 more

Precise control and study of molecules is challenging due to the variety of internal degrees of freedom and local coordinates that are typically not controlled in an experiment.Employing quantum gas microscopy to position and resolve the atoms in Rydberg macrodimer states solves most of these challenges and enables unique access to the molecular frame.Here, we demonstrate this approach and present photoassociation studies in which the molecular orientation relative to an applied magnetic field, the polarization of the excitation light, and the initial atomic state are fully controlled.The observed dependencies allow for an electronic structure tomography of the molecular state.We additionally observe an orientation-dependent Zeeman shift, and we reveal a significant influence on it caused by the hyperfine interaction of the macrodimer state.Finally, we demonstrate control over the electrostatic binding potential by engineering a gap between two crossing pair potentials.Our results establish macrodimers as the most sensitive tool to benchmark Rydberg interaction potentials, and they open new perspectives for improving Rydberg dressing schemes.Precise control and study of molecules is challenging due to the variety of internal degrees of freedom and local coordinates that are typically not controlled in an experiment.Employing quantum gas microscopy to position and resolve the atoms in Rydberg macrodimer states solves most of these challenges and enables unique access to the molecular frame.Here, we demonstrate this approach and present photoassociation studies in which the molecular orientation relative to an applied magnetic field, the polarization of the excitation light, and the initial atomic state are fully controlled.The observed dependencies allow for an electronic structure tomography of the molecular state.We additionally observe an orientation-dependent Zeeman shift, and we reveal a significant influence on it caused by the hyperfine interaction of the macrodimer state.Finally, we demonstrate control over the electrostatic binding potential by engineering a gap between two crossing pair potentials.Our results establish macrodimers as the most sensitive tool to benchmark Rydberg interaction potentials, and they open new perspectives for improving Rydberg dressing schemes.

arXiv:2010.02144Physical Review ResearchMar 18, 202113 citations

In some recent experiments an ultracold gas of

^{40}

_2

(or

^{6}

_2

) molecules has been produced from a degenerate two-component Fermi gas of

^{40}

K (or

^{6}

Li) atoms by adiabatic passage through a Feshbach resonance. The maximum atom-molecule transfer efficiency is reported to be about 50%. We propose a simple microscopic model to characterize the ground state of the gas in the vicinity of the resonance, and show that the term describing the atom-molecule coupling is responsible for the observed efficiency 50%. Our result also suggests that the experiments have produced a molecular condensate.

In a recent experiment at JILA [E. A. Donley et al., Nature (London) 417, 529 (2002)] an initially pure condensate of

{}^{85}\mathrm{Rb}

atoms was exposed to a specially designed time-dependent magnetic-field pulse in the vicinity of a Feshbach resonance. The production of additional components of the gas as well as their oscillatory behavior have been reported. We apply a microscopic theory of the gas to identify these components and determine their physical properties. Our time-dependent studies allow us to explain the observed dynamic evolution of all fractions, and to identify the physical relevance of the pulse shape. Based on ab initio predictions, our theory strongly supports the view that the experiments have produced a molecular condensate.