Assembly of Ultracold Molecules

Dipolar ultracold molecules are a powerful tool to direct observe exotic phenomena and to emulate different quantum systems with large control on all parameters. In our lab we aim to cool down 23Na39K molecules down to the hyperfine-ro-vibrational electronic ground state and employ them to unveil these phenomena.

Everything starts from hot samples of sodium and potassium that are collected in our main vacuum chamber after an initial cooling stage via Zeeman slowing and 2D-MOT trapping for 23Na and 39K, respectively. After laser cooling below Doppler limit, the atoms are loaded in a plugged magnetic quadrupole trap where the direct cooling of 23Na via microwave evaporation allows to cool the whole mixture thank to sympathetic cooling of potassium. 

  When the mixture reaches a temperature of some tens of microkelvin, collisions between sodium and potassium are too strong and we have to tune them by involving a magnetic Feshbach resonance. First we load the atoms into a crossed dipole trap and we apply a bias field with magnitude up to 900G. Thanks to this trick we could create the first doubly degenerate mixture of sodium and potassium. Cold mixtures allow us also to investigate for the fist time the collisional properties of 23Na and 39K in different hyperfine state combinations and compare our observations with recent theoretical predictions of our precious collaborators.  

Next steps are the formation of Feshbach shallow-bound molecules and the subsequent transfer to the ground state via stimulated adiabatic Raman passage (STIRAP). The lasers are ready to this step and moreover we will be able to see single molecules in the optical lattice thanks to our already tested large numerical aperture objective.

 A lot of work is on the way but we are closer than ever to the goal.

The Team

Principle Investigators

Prof. Dr. Silke Ospelkaus-Schwarzer
Gruppenleitung
Institut für Quantenoptik
Adresse
Welfengarten 1
30167 Hannover
Prof. Dr. Silke Ospelkaus-Schwarzer
Gruppenleitung
Institut für Quantenoptik
Adresse
Welfengarten 1
30167 Hannover
Dr. Leon Karpa
Gruppenleitung
Institut für Quantenoptik
Adresse
Welfengarten 1
30167 Hannover
Gebäude
Raum
Adresse
Welfengarten 1
30167 Hannover
Gebäude
Raum

Ph.D. Students

Mara Meyer zum Alten Borgloh
Wissenschaftliche Mitarbeiterinnen und Mitarbeiter
Institut für Quantenoptik
Adresse
Welfengarten 1
30167 Hannover
Gebäude
Raum
Adresse
Welfengarten 1
30167 Hannover
Gebäude
Raum
Jule Heier
Wissenschaftliche Mitarbeiterinnen und Mitarbeiter
Institut für Quantenoptik
Adresse
Welfengarten 1
30167 Hannover
Gebäude
Raum
Adresse
Welfengarten 1
30167 Hannover
Gebäude
Raum

Publications

Article

  • Kai K. Voges, Philipp Gersema, Torsten Hartmann, Silke Ospelkaus, and Alessandro Zenesini (2022): Hyperfine dependent atom-molecule loss analyzed by the analytic solution of few-body loss equationsPhysical Review Research 4, 023184 (2022)
    DOI: https://doi.org/10.1103/PhysRevResearch.4.023184
    arXiv: arXiv:2109.03605
  • Philipp Gersema, Kai K. Voges, Mara Meyer zum Alten Borgloh, Leon Koch, Torsten Hartmann, Alessandro Zenesini, Silke Ospelkaus, Junyu Lin, Junyu He, and Dajun Wang (2021): Probing photoinduced two-body loss of ultracold non-reactive bosonic 23Na87Rb and 23Na39K moleculesPhysical Review Letters
    DOI: https://doi.org/10.1103/PhysRevLett.127.163401
    arXiv: 2103.00510
  • Kai K. Voges, Philipp Gersema, Mara Meyer zum Alten Borgloh, Torben A. Schulze, Torsten Hartmann, Alessandro Zenesini, and Silke Ospelkaus (2020): Ultracold Gas of Bosonic 23Na39K Ground-State MoleculesPhysical Review Letters
    DOI: https://doi.org/10.1103/PhysRevLett.125.083401
    arXiv: 2008.05439
  • Kai K. Voges, Philipp Gersema, Torsten Hartmann, Torben A. Schulze, Alessandro Zenesini, and Silke Ospelkaus (2020): Formation of ultracold weakly bound dimers of bosonic 23Na39KPhys. Rev. A 101, 042704
    DOI: 10.1103/PhysRevA.101.042704
  • Kai K. Voges, Philipp Gersema, Torsten Hartmann, Torben A. Schulze, Alessandro Zenesini and Silke Ospelkaus (2019): A pathway to ultracold bosonic 23Na39K ground state moleculesNew J. Phys. 21 (2019) 123034
    DOI: 10.1088/1367-2630/ab5f31
  • M. W. Gempel, T. Hartmann, T. A. Schulze, K. K. Voges, A. Zenesini, and S. Ospelkaus (2019): An adaptable two-lens high-resolution objective for single-site resolved imaging of atoms in optical latticesReview of Scientific Instruments 90, 053201 (2019)
    DOI: 10.1063/1.5086539
  • Torsten Hartmann, Torben A. Schulze, Kai K. Voges, Philipp Gersema, Matthias W. Gempel, Eberhard Tiemann, Alessandro Zenesini, Silke Ospelkaus (2019): Feshbach resonances in 23Na+39K mixtures and refined molecular potentials for the NaK moleculePhys. Rev. A 99 (2019), 032711
    DOI: 10.1103/PhysRevA.99.032711
    arXiv: 1810.00608
  • T.A. Schulze, T. Hartmann, K.K. Voges, M.W. Gempel, E. Tiemann, A. Zenesini, and S. Ospelkaus (2018): Feshbach spectroscopy and dual-species Bose-Einstein condensation of 23Na-39K mixturesPhys. Rev. A 97, 023623
    DOI: 10.1103/PhysRevA.97.023623
  • M.W. Gempel, T. Hartmann, T.A. Schulze, K.K. Voges, A. Zenesini, S. Ospelkaus (2016): Versatile electric fields for the manipulation of ultracold NaK moleculesNew J. Phys. 18 (2016) 045017
    DOI: 10.1088/1367-2630/18/4/045017
    arXiv: arXiv:1603.08348
  • T.A. Schulze, I.I. Temelkov, M.W. Gempel, T. Hartmann, H. Knöckel, S. Ospelkaus, and E. Tiemann (2013): Multichannel modeling and two photon coherent transfer paths in NaKPhys. Rev. A 88, 023401 (2013), DOI: http://dx.doi.org/10.1103/PhysRevA.88.023401 Weitere Informationen