Efficient pathway to NaCs ground state molecules

We present a study of two-photon pathways for the transfer NaCs molecules to their rovibrational ground state. Starting from Feshbach molecules, we perform bound-bound excited state spectroscopy in wavelength range 900~nm 940~nm, covering more than 30 vibrational states $c \, ^3\Sigma^+$, $b ^3\Pi$, and $B ^1\Pi$ electronic states. Analyzing rotational substructure, identify highly mixed ^3\Sigma^+_1 |v=22 \rangle \sim b ^3\Pi_1 | v=54\rangle$ as an efficient bridge stimulated Raman adiabatic passage (STIRAP). demonstrate into with efficiency up 88(4)\%. Highly is critical realization many-body quantum phases strongly dipolar high fidelity detection single example, spin physics experiments optical lattices information tweezer arrays.