High-resolution molecular spectroscopy for producing ultracold absolute-ground-state Na 23 Rb 87 molecules

摘要: We report a detailed molecular spectroscopy study of the lowest excited electronic states $^{23}\mathrm{Na}\phantom{\rule{0.16em}{0ex}}^{87}\mathrm{Rb}$ for producing ultracold molecules in electronic, rovibrational, and hyperfine ground state. Starting from weakly bound Feshbach molecules, series vibrational levels $A{\phantom{\rule{0.16em}{0ex}}}^{1}{\mathrm{\ensuremath{\Sigma}}}^{+}\text{\ensuremath{-}}b{\phantom{\rule{0.16em}{0ex}}}^{3}\mathrm{\ensuremath{\Pi}}$ coupled is investigated. After resolving, modeling, interpreting structure several lines, we successfully identify long-lived level resulting accidental coupling between ${0}^{+}$ ${0}^{\ensuremath{-}}$ components $b{\phantom{\rule{0.16em}{0ex}}}^{3}\mathrm{\ensuremath{\Pi}}$ state, satisfying all requirements population transfer toward rovibrational $X{\phantom{\rule{0.16em}{0ex}}}^{1}{\mathrm{\ensuremath{\Sigma}}}^{+}$ Using two-photon spectroscopy, its binding energy measured to be 4977.308(3) ${\mathrm{cm}}^{\ensuremath{-}1}$. calibrate transition strengths carefully also demonstrate Raman absolute