An observation of a series of single and multi photon molecular transitions

Microwave transitions between pair states composed of two Rb Rydberg atoms in a magneto-optical trap are investigated. This is an extension of the experiment that investigated the transition from ndnd to (n+1)d(n-2)f state. The aforementioned transition is allowed because (n+2)p(n-2)f state that is energetically close to ndnd state gets admixed into ndnd state as a result of the dipole-dipole induced configuration interaction. The microwave transition is from the (n+2)p(n-2)f part of the wavefunction to the (n+1)d(n-2)f state. In the transition, the microwave drives a transition from (n+2)p to another state in one atom with the other atom remaining a spectator in the (n-2)f state. A series of one, two, and three photon molecular transitions that occur due to the same mechanism was observed. Those are transitions from ndnd to (n+3)s(n-2)f, (n+3)p(n-2)f, nf(n-2)f, and (n+4)s(n-2)f. In addition, molecular transitions during which the microwave drives a transition from (n-2)f to another state in one atom with the other atom remaining a spectator in the (n+2)p state were also observed. The molecular transitions of this type that were observed are ndnd to (n+2)p(n-1)d and (n+2)p(n-1)f. The measured transition frequencies were found to agree well with the calculated values.