A protocol to realize triatomic ultralong range Rydberg molecules in an ultracold KRb gas

Abstract

We propose an experimentally realizable scheme to produce triatomic ultralong-range Rydberg molecules (TURM), formed in ultracold KRb traps. A near resonant coupling of the non-zero quantum defect Rydberg levels with the KRb molecule in N = 0 and N = 2 rotational levels, is engineered which exploits the unique Rydberg electron–molecule anisotropic dipole interaction. This near resonant coupling enhances the TURM binding and produces favorable Franck–Condon factors. Schemes for both postassium and rubidium excitations are demonstrated.