High-resolution spectroscopy of Rydberg molecular states of Rb285 near the 5s+7p asymptote

Abstract

Rydberg molecules, often exemplified by long-range "trilobite" molecules, are a subject of much recent interest at high principal quantum number n. States that use the same bonding mechanism can exist at much lower n and less-extreme internuclear separations that are still quite long range. We use a high-resolution pulsed amplifier to study previously-detected transitions to a low-n Rydberg molecular state near the 5s + 7p asymptote in 85 Rb2. The observed line structure is modeled using precise ground-state positions and a lower bound of τ > 1.1 × 10 −9 s is set on the excited-state autoionization lifetime.

Long-range Rydberg molecule Rb$_2$: Two-electron \textit{R}-matrix calculations at intermediate internuclear distances

“…The differences at R < 40 a.u. between the PECs presented here and those published in the reference [18] suggest that other interpretation of the experimental spectra than proposed in the references [18,19] might be plausible.…”

“…This can be illustrated on the electronic state with the asymptotic energy 5s + 7p that is subject of the detailed analysis by Carollo et al [19]. Corresponding zero-range PEC, displayed in Fig.…”

“…This range of small R is relevant in the context of the experimental studies by Bellos et al [18] and Carollo et al [19]. The authors attempt to identify the Rb 2 LR-RMs for R < ∼ 50 a.u.…”

“…3, shows a potential barrier and a potential well. Carollo et al [19] calculated the vibrational states localized left of the barrier (inner states) and inside the potential well (outer states). Their vibrational energies were assigned to the observed peaks in the experimental spectra and the long-range Rydberg states were, depending on their localization, characterized as inner or outer.…”

“…The information about the populations of different electronic and vibrational energy levels of the LRRMs was retrieved using the autoionization spectroscopy of the molecular cations Rb + 2 . Later, the states slightly red-shifted with respect to the 5s + 7p energy were studied in more detail by Carollo et al [19].…”