Creation of ultracold $^{87}$RbCs molecules in the rovibrational ground state

摘要

We report the creation of a sample of over 1000 ultracold $^{87}$RbCsmolecules in the lowest rovibrational ground state, from an atomic mixture of$^{87}$Rb and Cs, by magnetoassociation on an interspecies Feshbach resonancefollowed by stimulated Raman adiabatic passage (STIRAP). We measure the bindingenergy of the RbCs molecule to be $h c \times 3811.576(1)$ cm$^{-1}$ and the$|v''=0, J''=0>$ to $|v''=0, J''=2>$ splitting to be $h \times 2940.09(6)$ MHz.Stark spectroscopy of the rovibrational ground state yields an electric dipolemoment of 1.225(3)(8) D, where the values in parentheses are the statisticaland systematic uncertainties, respectively. We demonstrate that a space-fixeddipole moment of 0.355(2)(4) D is accessible in RbCs, which is substantiallyhigher than in previous work.