Research
Ultracold Polar Molecules
The molecule of choice for us is the bosonic 23Na87Rb, which has a rather large dipole moment of 3.3 Debye. Because of its relatively small rotational constant, it is also quite easy to polarize. At a field of only 5kV/cm, the effective dipole is ~ 2 Debye. This gives us the ability to tune the inter-molecular interactions over a large range.
In their lowest energy state, NaRb molecules are stable against two-body exchange chemical reactions. This provides us the freedom to study ultracold molecular collisions with distinguishable inelastic channels. For instance, by preparing molecules in higher nuclear spins, rotational or vibrational levels and observing the respective losses, we could verify the universal collision model for ultracold molecules in different scenarios.
For the ground state molecule preparation, we plan to follow a 3-steps scheme
- Prepare ultracold atomic mixtures;
- Form weakly bound heteronuclear molecules with Feshbach association;
- Coherent population transfer to the ground state by STIRAP.
Recently, we have successfully created a sample of ground-state NaRb molecules. A dipole moment of > 1 Debye is also demonstrated. For details, please see our paper on arXiv:1602.03947. The STIRAP path is as shown in this figure.
Spinor Mixtures
Coming soon.
Few-body physics
Coming soon.