Enlarging the tool box of ultracold molecule manipulation

We present our recent progress on preparing ultracold gases of dipolar fermionic $^{23}$Na$^{40}$K molecules in 3D optical lattices and manipulating their rotational degrees of freedom. We have indentified a tune-out wavelength at which the polarizability of the first excited rotational state vanishes, while polarizability of the ground state remains finite. The tune-out wavelength is located close to the $X^1 \Sigma^+, v=0, J=0 \to b^3 \Pi, v=0, J=1, \Omega=1$ transition at 866.14 nm. The small line width of this transition makes it a good candidate for rotation-dependent dipole traps and lattices. In combination with our recent work on increasing the filling of NaK molecules in a 3D lattice, this brings us closer to simulating lattice spin models with dipolar molecules.