We present a mechanism contributing to the detection of photoassociated long-range Rydberg molecules via pulsed-field ionization: ionic products, created by the decay of a long-range Rydberg molecule, modify the excitation spectrum of surrounding ground-state atoms and facilitate the excitation of further atoms into Rydberg states by the photoassociation light. Such an ion-mediated excitation mechanism has been previously called a Coulomb antiblockade. Pulsed-field ionization typically does not discriminate between the ionization of a long-range Rydberg molecule and an isolated Rydberg atom, and thus the number of atomic ions detected by this mechanism is not proportional to the number of long-range Rydberg molecules present in the probe volume. By combining high-resolution UV and rf spectroscopy of a dense, ultracold gas of cesium atoms, theoretical modeling of the molecular-level structures of long-range Rydberg molecules bound below $n\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}$ Rydberg states of cesium, and a rate model of the photoassociation and decay processes, we unambiguously identify the signatures of this detection mechanism in the photoassociation of long-range Rydberg molecules bound below atomic asymptotes with negative Stark shifts.We present a mechanism contributing to the detection of photoassociated long-range Rydberg molecules via pulsed-field ionization: ionic products, created by the decay of a long-range Rydberg molecule, modify the excitation spectrum of surrounding ground-state atoms and facilitate the excitation of further atoms into Rydberg states by the photoassociation light. Such an ion-mediated excitation mechanism has been previously called a Coulomb antiblockade. Pulsed-field ionization typically does not discriminate between the ionization of a long-range Rydberg molecule and an isolated Rydberg atom, and thus the number of atomic ions detected by this mechanism is not proportional to the number of long-range Rydberg molecules present in the probe volume. By combining high-resolution UV and rf spectroscopy of a dense, ultracold gas of cesium atoms, theoretical modeling of the molecular-level structures of long-range Rydberg molecules bound below $n\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}$ Rydberg states of cesium, and a rate model of the photoassociation and decay processes, we unambiguously identify the signatures of this detection mechanism in the photoassociation of long-range Rydberg molecules bound below atomic asymptotes with negative Stark shifts.

arXiv:2211.04744Physical Review AJan 18, 20236 citations

Long Range Rydberg Molecules

Hyunwook Park, Thomas F. Gallagher

Bulletin of the American Physical SocietyJun 5, 20122 citations

Long-range Rydberg-Rydberg interactions and molecular resonances

Jovica Stanojevic, Robin Côté, D. Tong +3 more

The European Physical Journal DJun 20, 200639 citations

Spectroscopy of ⁸⁷Sr Rydberg Atoms and Molecules

Roger Ding

Spectroscopy of ⁸⁷Sr Rydberg Atoms and Molecules This dissertation describes the development of an apparatus to undertake spectroscopic studies of ⁸⁷Sr Rydberg states and their application in the production of ultra-long-range Rydberg molecules (ULRRMs). Most previous spectroscopic studies of strontium have been performed with the bosonic isotope ⁸⁸Sr which has no nuclear spin (I=0), resulting in a relatively simple and well-understood Rydberg excitation spectrum. In contrast, fermionic ⁸⁷Sr has a large nuclear spin (I=9/2) that leads to strong hyperfine interactions which greatly complicate the Rydberg excitation spectrum. In order to understand the Rydberg states in ⁸⁷Sr, two-photon spectroscopy was performed to measure and identify the (5sns)³S and (5snd)³D hyperfine Rydberg states for 30≲n≲99. Working with theory collaborators, a detailed understanding of how the hyperfine interaction affects the Rydberg levels is developed and used to extract revised quantum defects. The detailed understanding of the ⁸⁷Sr hyperfine Rydberg structure was exploited to produce the first ULRRMs in a fermionic gas. Unlike traditional molecular binding mechanisms, ULRRMs comprise of one or more ground-state atoms embedded in the electron cloud of a Rydberg atom with the entire system bound together through the weak Rydberg electron-neutral atom scattering. Therefore, production of ULRRMs is dependent on both the principal quantum number (n) of the parent Rydberg atom and the initial spatial distribution of atoms. At low temperatures, the effects of quantum statistics becomes important and result in bunching (bosons) and antibunching (fermions). These differences in spatial distributions can influence the excitation rates of ULRRMs. Current progress in exploring the role of quantum statistics in the excitation of ULRRMs using cold, dense strontium gases is described, with an emphasis on ⁸⁷Sr, and how such measurements can be used to extract the pair correlation function g⁽²⁾(R).Spectroscopy of ⁸⁷Sr Rydberg Atoms and Molecules This dissertation describes the development of an apparatus to undertake spectroscopic studies of ⁸⁷Sr Rydberg states and their application in the production of ultra-long-range Rydberg molecules (ULRRMs). Most previous spectroscopic studies of strontium have been performed with the bosonic isotope ⁸⁸Sr which has no nuclear spin (I=0), resulting in a relatively simple and well-understood Rydberg excitation spectrum. In contrast, fermionic ⁸⁷Sr has a large nuclear spin (I=9/2) that leads to strong hyperfine interactions which greatly complicate the Rydberg excitation spectrum. In order to understand the Rydberg states in ⁸⁷Sr, two-photon spectroscopy was performed to measure and identify the (5sns)³S and (5snd)³D hyperfine Rydberg states for 30≲n≲99. Working with theory collaborators, a detailed understanding of how the hyperfine interaction affects the Rydberg levels is developed and used to extract revised quantum defects. The detailed understanding of the ⁸⁷Sr hyperfine Rydberg structure was exploited to produce the first ULRRMs in a fermionic gas. Unlike traditional molecular binding mechanisms, ULRRMs comprise of one or more ground-state atoms embedded in the electron cloud of a Rydberg atom with the entire system bound together through the weak Rydberg electron-neutral atom scattering. Therefore, production of ULRRMs is dependent on both the principal quantum number (n) of the parent Rydberg atom and the initial spatial distribution of atoms. At low temperatures, the effects of quantum statistics becomes important and result in bunching (bosons) and antibunching (fermions). These differences in spatial distributions can influence the excitation rates of ULRRMs. Current progress in exploring the role of quantum statistics in the excitation of ULRRMs using cold, dense strontium gases is described, with an emphasis on ⁸⁷Sr, and how such measurements can be used to extract the pair correlation function g⁽²⁾(R).

Sep 16, 20191 citation

n\phantom{\rule{0.16em}{0ex}}^{2}P_{3/2}

Rydberg states of cesium, and a rate model of the photoassociation and decay processes, we unambiguously identify the signatures of this detection mechanism in the photoassociation of long-range Rydberg molecules bound below atomic asymptotes with negative Stark shifts.