Formation of ultracold ${\mathrm{Cs}}_2$ molecules through the double-minimum ${\mathrm{Cs}}_2$ $3{}^1{\Sigma }_u^{+}$ state

We present a simple model of ultracold cesium dimer formation in which the photoassociation into rovibrational levels of the double-minimum ${\mathrm{Cs}}_2$ $3{}^1{\Sigma }_u^{+}$ state above its internal barrier enables spontaneous or stimulated emission into the lowest rovibrational levels of the ${\mathrm{Cs}}_2$ $1\left(X\right)\mathrm{}{}^1{\Sigma }_g^{+}$ ground electronic state. The transition dipole moment should be sufficiently large for observation of such spectral transitions. The use of the ${\mathrm{Cs}}_2$ $3{}^1{\Sigma }_u^{+}$ double-minimum potential could be extended to molecular Bose-Einstein condensates in which an optical trap can be employed for trapping of both atomic and molecular species.