Observation of Feshbach resonances in ultracold <sup>107</sup>Ag collisions
ORAL
Abstract
The alkali-like electronic structure of silver (Ag), combined with its large electron affinity, makes it well suited for forming highly polar molecules with alkali atoms using well-established ultracold bi-alkali assembly techniques [1]. Such molecules are predicted to have electric dipole moments of up to ~10 Debye and beyond, rendering them exceptionally attractive for applications in quantum simulation and precision measurement [1,2]. For example, FrAg is extremely sensitive to new physics beyond the Standard Model [3, 4].
Creating such “ultrapolar” molecules requires full quantum control over collisional properties of Ag atoms. Towards achieving this control, we have implemented a dark SPOT MOT to trap ~109 Ag atoms, of both isotopes: 109Ag [5] and 107Ag. We also have implemented Λ-enhanced gray molasses cooling on the D1 line in both isotopes, achieving temperatures of ~15 μK. These temperatures enable optical dipole trapping of ~106 Ag atoms of either isotope. With these atoms, we report the first observation of Feshbach resonances in 107Ag. We discuss the implications for achieving full control over ultracold Ag-Ag collisions, and progress towards the realization of a BEC of Ag atoms.
[1] J. Kłos et al., New J. Phys. 24, 025005 (2022).
[2] M. Śmiałkowski and M. Tomza, Phys. Rev. A 103, 022802 (2021).
[3] A. Marc and T. Fleig, Eur. Phys. J. D 78(3), 19 (2025).
[4] V. Spevak et al., Phys. Rev. C 56, 1357 (1997).
[5] M. Vayninger et al., Phys. Rev. A 112, 063306 (2025).
Creating such “ultrapolar” molecules requires full quantum control over collisional properties of Ag atoms. Towards achieving this control, we have implemented a dark SPOT MOT to trap ~109 Ag atoms, of both isotopes: 109Ag [5] and 107Ag. We also have implemented Λ-enhanced gray molasses cooling on the D1 line in both isotopes, achieving temperatures of ~15 μK. These temperatures enable optical dipole trapping of ~106 Ag atoms of either isotope. With these atoms, we report the first observation of Feshbach resonances in 107Ag. We discuss the implications for achieving full control over ultracold Ag-Ag collisions, and progress towards the realization of a BEC of Ag atoms.
[1] J. Kłos et al., New J. Phys. 24, 025005 (2022).
[2] M. Śmiałkowski and M. Tomza, Phys. Rev. A 103, 022802 (2021).
[3] A. Marc and T. Fleig, Eur. Phys. J. D 78(3), 19 (2025).
[4] V. Spevak et al., Phys. Rev. C 56, 1357 (1997).
[5] M. Vayninger et al., Phys. Rev. A 112, 063306 (2025).
*We acknowledge support from NSF and the "Table-top experiments for fundamental physics" program, sponsored by the Gordon and Betty Moore Foundation, Simons Foundation, Alfred P. Sloan Foundation, and John Templeton Foundation.
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Publication: Vayninger, M., Xiang, A., Bhanushali, N.D., Chen, X., Verma, M., Yang, S., Kapur, R.T., DeMille, D. and Yan, Z.Z. (2025). Magneto-optical trap of silver and potassium atoms. PRA, 112, 063306
Presenters
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Mohit Verma
- University of Chicago