Group seminar at MPQ and Zoom: Efficient Creation of Ultracold Ground-State 6Li-40K Polar Molecules

Dr. Anbang Yang, National University of Singapore
Group seminar at MPQ lecture hall and Zoom
Tuesday, July 25, 09:00 am (MEZ)

Abstract:

Ultracold polar molecules with their long-range anisotropic dipole-dipole interactions are excellent testbeds for research on quantum simulation of many-body physics, quantum chemistry and quantum information processing. In this talk, we present our work in Singapore on the creation of ultracold LiK molecules in their ro-vibrational ground state. Weakly-bound LiK molecules are first magnetically associated from an ultracold mixture of Li and K atoms via a Feshbach resonance at 21.56 mT in a crossed dipole trap. To coherently transfer these molecules to their singlet ro-vibrational ground state, we explored an excited state molecular potential with pure singlet spin character. Using polarization laser spectroscopy, an ideal Lambda-shaped three-level-system for the stimulated-Raman adiabatic passage (STIRAP) can be established. The Raman lasers are stabilized simultaneously to a home-built high-finesse cavity. By comparison with a frequency comb, sub-kHz linewidths of both lasers can be confirmed. Further, the residual fast phase-noise of the Raman lasers is characterized and reduced by extending the cavity length of the diode lasers. Recently, STIRAP ground state transfer for LiK molecules with efficiency up to 98% has been observed.