Observation of photoassociation spectroscopy of ultralong 37 D 5/2 + 6 S 1/2 Cs 2 Rydberg molecules

Abstract

We present an experimental observation of 37D5/2 + 6S1/2 Cs2 Rydberg-ground molecules by employing a two-photon photoassociation method. Two distinct Rydberg-ground molecular signals, deep and shallow bound molecules, are observed at the red detuning of atomic line. In theory, the model of scattering interaction between the Rydberg electron and ground-state atom is used to simulate the experiments. Two potential energy curves with energy minimum, deep pure triplet 3ς and shallow hyperfine-mixed singlet-triplet 1,3ς potentials, refer to the attained Rydberg-ground molecular signals, respectively. Calculations of the binding energy of triplet 3ς and mixed 1,3ςv = 0 states are compared with the measurements. The agreement between the calculated and measured values of the binding energy yields zero-energy scattering lengths asT(0) = -19.2a0 and asS(0) = -1.3a0, respectively.