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Precise characterization of 6Li Feshbach resonances using trap-sideband-resolved RF spectroscopy of weakly bound
1Physikalisches Institut, Ruprecht-Karls-Universität Heidelberg, 69120 Heidelberg, Germany.
Physical Review Letters
|April 16, 2013
Summary
We precisely measured the binding energy of lithium-6 (6Li2) Feshbach molecules. This improved accuracy refines understanding of strongly interacting Fermi gases and the Bertsch parameter.
Area of Science:
- Atomic, Molecular, and Optical Physics
- Quantum Gases
- Condensed Matter Physics
Background:
- Weakly bound Feshbach molecules are crucial for studying strongly interacting Fermi gases.
- Previous measurements of the Bertsch parameter have uncertainties.
- Precise determination of molecular binding energies is essential for theoretical models.
Purpose of the Study:
- To develop a novel technique for high-precision measurement of Feshbach molecule binding energies.
- To refine the 6Li scattering potential using experimental data.
- To improve the accuracy of the Bertsch parameter for strongly interacting Fermi gases.
Main Methods:
- Radio-frequency dissociation spectroscopy of lithium-6 (6Li2) Feshbach molecules in an optical dipole trap.
- High magnetic field stability enabling resolution of discrete trap levels.
- Coupled-channel calculations to fit the 6Li scattering potential.
Main Results:
- Achieved unprecedented precision in determining Feshbach molecule binding energies.
- Determined 6Li Feshbach resonance pole positions with accuracy better than 7×10(-4) of resonance widths.
- Provided a corrected value for the Bertsch parameter ξ = 0.370(5)(8).
Conclusions:
- The novel spectroscopy technique significantly reduces uncertainties in Feshbach molecule properties.
- The refined scattering potential and Bertsch parameter have important consequences for understanding Fermi gases.
- This work eliminates a dominant uncertainty in precision measurements of the equation of state for Fermi gases.
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