High-Resolution Spectroscopy of Trilobite-Like States of $^{85}$Rb$_2$

We present high-resolution spectra of low-$n$ trilobite-like states in $^{85}$Rb$_2$. Trilobite states are novel long-range molecular states consisting of a ground-state atom embedded in the Rydberg wavefunction of a second atom. We utilize a bound-bound excitation to populate these states from photoassociated ultracold molecules in high-$v$ levels of the lowest triplet state. The excitation is stimulated by a frequency-doubled pulse-amplified CW laser for narrow linewidth. Upon excitation, the trilobite-like states rapidly autoionize and are mass-selectively detected by an ion detector. Previous detection of these states was done by a broader linewidth conventional pulsed laser as reported in Ref. [1]. This work is supported by the NSF and AFOSR.\\[4pt] [1] M. A. Bellos \textit{et al.}, Phys. Rev. Lett. \textbf{111}, 053001 (2013)