Towards ultracold ground-state NaRb molecule

The ground-state $^{23}$Na$^{87}$Rb molecule is chemically stable and has a permanent electric dipole moment as large as 3.3 Debye. These properties make it a promising candidate for investigating dipolar quantum gases. Recently, we have realized weakly bound $^{23}$Na$^{87}$Rb Feshbach molecules via magneto-association. Here, we will present our results on excited-state molecular spectroscopy investigation starting with these Feshbach molecules. The prospects of transferring $^{23}$Na$^{87}$Rb to the absolute ground state will also be discussed.