Theoretical and Experimental evidence for the observation of trilobite states in Cs

A novel binding mechanism arises from the attractive, low-energy scattering of a Rydberg electron from a neighboring ground state atom. The states formed by this binding mechanism are referred to as trilobite or trilobite-like states. A primary difference between the trilobite and trilobite-like states is the angular momentum of the Rydberg atom, which is dominated by an s-wave Rydberg orbit. The larger angular momentum of trilobite states can change the properties of the molecules that form. For example, large $l$ trilobite molecules are predicted to have giant, body-fixed permanent dipole moments ($\sim 1 $kD). Trilobite-like states were observed in 2009 in Rb [1]. We present experimental evidence for trilobite molecules formed as a result of state mixing between the $nS$ and $(n-4)\ge F$ states in Cs, due to the small non-integer quantum defects in the Cs s state, and compare the observation with theoretical results. \\[4pt] [1] V. Bendkowsky et al. Nature 458, 1005 (2009)