© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

arXiv:1909.04634 · Journal of Physics B Atomic Molecular and Optical Physics

Creation of vibrationally-excited ultralong-range Rydberg molecules in polarized and unpolarized cold gases of 87 Sr

R Ding, S K Kanungo, J D Whalen, T. C. Killian, F B Dunning, S Yoshida, Joachim Burgdörfer

Published Dec 4, 2019• 10 citations

Abstract

Abstract Photoexcitation rates for creation of ultralong-range Rydberg molecules with 31 ≲ n ≲ 41 in both ground and excited vibrational levels in cold ( T ∼ 900 nK) gases of polarized and unpolarized 87 Sr are presented. The measured production rates of the ν = 0, 1 and 2 vibrational levels reveal rather different n dependences which are analyzed by evaluating the Franck–Condon factors associated with excitation of the different vibrational levels and molecular rotational states. In particular, for gases of spin-polarized fermions, only Rydberg dimers with odd rotational quantum numbers are excited due to the requirement that their wave functions be anti-symmetric with respect to exchange. The data also demonstrate that measurements of the formation of vibrationally-excited ν = 1 molecules can furnish a probe of pair correlations over intermediate length scales.

DOI: 10.1088/1361-6455/ab53b5

Related papers

Excitation of vibrationally-excited ultralong-range strontium Rydberg molecules in quantum gases

Roger Ding, J. D. Whalen, S. K. Kanungo +4 more

Synopsis The photoexcitation rate for ultralong-range Rydberg molecules is sensitive to the initial spatial sepa-ration of the atoms from which they are formed. Here we explore the photoexcitation of different molecular vibrational states as a probe of spatial correlations in a cold atomic gas.

Journal of Physics Conference Series•Jan 1, 2020•0 citations

Formation of ultralong-range fermionic Rydberg molecules in 87Sr: role of quantum statistics

J. D. Whalen, Roger Ding, S. K. Kanungo +4 more

Measurements of ultralong-range Rydberg molecule formation in cold gases of fermionic 87Sr atoms are presented. Measurements undertaken using polarised and unpolarised cold atom samples demonstrate that studies of Rydberg molecule formation can provide a window into the important role played by quantum statistics in determining the pair-correlation function, g(2)(R), and, more generally, can furnish a sensitive probe of spatial correlations in quantum gases that is suitable for use in a number of different applications.

Molecular Physics•Feb 3, 2019•12 citations

Photoassociation of Sr 84 n 1 D 2 ultralong-range Rydberg dimers

C. Wang, Ang Li, S. K. Kanungo +3 more

Measurements of the production of 5 s n d 1 D 2 – 5 s 2 1 S 0 ultralong-range Rydberg dimers through photoassocation in an ultracold Sr 84 atomic gas are reported. The molecular potential associated with the Rydberg D state is anisotropic and the molecular states are characterized by the vibrational quantum number ν and the total angular momentum K ⃗ = L ⃗ + N ⃗ , where L ⃗ and N ⃗ are the electronic orbital angular momentum and rotational angular momentum, respectively. The measured molecular binding energies agree reasonably well with theoretical predictions. Additionally, the electron-atom scattering leads to broader line shapes in the photoassociation spectrum than might be expected simply from the angular momentum of the initial colliding cold-atom pairs.

Physical Review A•Apr 7, 2026•1 citation

Probing nonlocal spatial correlations in quantum gases with ultra-long-range Rydberg molecules

J. D. Whalen, S. K. Kanungo, Roger Ding +7 more

We present photoexcitation of ultra-long-range Rydberg molecules as a probe of spatial correlations in bosonic and fermionic quantum gases. Rydberg molecules can be created with well-defined internuclear spacing, set by the radius of the outer lobe of the Rydberg electron wave function ${R}_{n}$. By varying the principal quantum number $n$ of the target Rydberg state, the molecular excitation rate can be used to map the pair-correlation function of the trapped gas ${g}^{(2)}({R}_{n})$. We demonstrate this with ultracold Sr gases and probe pair-separation length scales in the range ${R}_{n}=1400--3200$ ${a}_{0}$, which are on the order of the thermal de Broglie wavelength for temperatures around 1 $\ensuremath{\mu}\mathrm{K}$. We observe bunching for a single-component Bose gas of ${}^{84}\mathrm{Sr}$ and antibunching due to Pauli exclusion at short distances for a polarized Fermi gas of ${}^{87}\mathrm{Sr}$, revealing the effects of quantum statistics.

arXiv:1903.11526•Physical Review A•Jul 22, 2019•35 citations

Probing nonlocal correlations with ultralong-range Rydberg molecules

J. D. Whalen

Ultracold atomic systems provide pristine environments for creating and manipulating strongly-interacting quantum systems. The flexibility and utility of ultracold atomic systems comes at the cost of isolation of the quantum system away from environmental perturbations inside of an ultra-high vacuum chamber. This isolation reduces the number of ways that these systems can be probed, in particular, there are relatively few ways to probe correlations in these systems at mesoscopic length scales. In this thesis we present a new technique for probing correlations in ultracold atomic gases using ultralong-range Rydberg molecules. We will present a description of the relevant experimental apparatus and techniques developed for laser cooling and trapping ultracold mixtures of Sr, and a brief theoretical discussion on the relationship between the pair correlation function $g^{(2)}(R)$ and the excitation rates of ultralong-range Rydberg molecules. We present two publications: the first on using ultralong-range Rydberg molecules to probe $g^{(2)}(R)$ in thermal gases, and the second on the creation of heteronuclear ultralong-range Rydberg molecules from a strongly interacting Bose mixture of $^{88}$Sr and $^{84}$Sr. Finally, we will present conclusions and a brief outlook for the future experiments utilizing this method.

•Jun 14, 2021•0 citations

Measurements of spatial correlations in quantum gases using ultralong-range strontium Rydberg molecules

J. D. Whalen, Roger Ding, S. K. Kanungo +4 more

Synopsis The photoexcitation of ultralong-range Rydberg molecules is demonstrated as a probe of spatial cor-relations in a quantum gas on previously inaccessible length scales of 1400-3200 a 0. Measurements using cold (∼1 μK) (fermionic) 87Sr and (bosonic) 84Sr reveal the effects of quantum statistics on the pair correlation function g (2)(R).

Journal of Physics Conference Series•Jan 1, 2020•0 citations

Abstract Photoexcitation rates for creation of ultralong-range Rydberg molecules with 31 ≲ n ≲ 41 in both ground and excited vibrational levels in cold ( T ∼ 900 nK) gases of polarized and unpolarized 87 Sr are presented. The measured production rates of the ν = 0, 1 and 2 vibrational levels reveal rather different n dependences which are analyzed by evaluating the Franck–Condon factors associated with excitation of the different vibrational levels and molecular rotational states. In particular, for gases of spin-polarized fermions, only Rydberg dimers with odd rotational quantum numbers are excited due to the requirement that their wave functions be anti-symmetric with respect to exchange. The data also demonstrate that measurements of the formation of vibrationally-excited ν = 1 molecules can furnish a probe of pair correlations over intermediate length scales.

Measurements of ultralong-range Rydberg molecule formation in cold gases of fermionic 87Sr atoms are presented. Measurements undertaken using polarised and unpolarised cold atom samples demonstrate that studies of Rydberg molecule formation can provide a window into the important role played by quantum statistics in determining the pair-correlation function, g(2)(R), and, more generally, can furnish a sensitive probe of spatial correlations in quantum gases that is suitable for use in a number of different applications.

Measurements of the production of 5 s n d 1 D 2 – 5 s 2 1 S 0 ultralong-range Rydberg dimers through photoassocation in an ultracold Sr 84 atomic gas are reported. The molecular potential associated with the Rydberg D state is anisotropic and the molecular states are characterized by the vibrational quantum number ν and the total angular momentum K ⃗ = L ⃗ + N ⃗ , where L ⃗ and N ⃗ are the electronic orbital angular momentum and rotational angular momentum, respectively. The measured molecular binding energies agree reasonably well with theoretical predictions. Additionally, the electron-atom scattering leads to broader line shapes in the photoassociation spectrum than might be expected simply from the angular momentum of the initial colliding cold-atom pairs.

We present photoexcitation of ultra-long-range Rydberg molecules as a probe of spatial correlations in bosonic and fermionic quantum gases. Rydberg molecules can be created with well-defined internuclear spacing, set by the radius of the outer lobe of the Rydberg electron wave function

{R}_{n}

. By varying the principal quantum number

n

of the target Rydberg state, the molecular excitation rate can be used to map the pair-correlation function of the trapped gas

{g}^{(2)}({R}_{n})

. We demonstrate this with ultracold Sr gases and probe pair-separation length scales in the range

{R}_{n}=1400--3200

{g}^{(2)}({R}_{n})

, which are on the order of the thermal de Broglie wavelength for temperatures around 1 $\ensuremath{\mu}\mathrm{K}$. We observe bunching for a single-component Bose gas of

{}^{84}\mathrm{Sr}

and antibunching due to Pauli exclusion at short distances for a polarized Fermi gas of

{}^{87}\mathrm{Sr}

, revealing the effects of quantum statistics.

Ultracold atomic systems provide pristine environments for creating and manipulating strongly-interacting quantum systems. The flexibility and utility of ultracold atomic systems comes at the cost of isolation of the quantum system away from environmental perturbations inside of an ultra-high vacuum chamber. This isolation reduces the number of ways that these systems can be probed, in particular, there are relatively few ways to probe correlations in these systems at mesoscopic length scales. In this thesis we present a new technique for probing correlations in ultracold atomic gases using ultralong-range Rydberg molecules. We will present a description of the relevant experimental apparatus and techniques developed for laser cooling and trapping ultracold mixtures of Sr, and a brief theoretical discussion on the relationship between the pair correlation function

g^{(2)}(R)

and the excitation rates of ultralong-range Rydberg molecules. We present two publications: the first on using ultralong-range Rydberg molecules to probe

g^{(2)}(R)

in thermal gases, and the second on the creation of heteronuclear ultralong-range Rydberg molecules from a strongly interacting Bose mixture of

^{88}

Sr and

^{84}

Sr. Finally, we will present conclusions and a brief outlook for the future experiments utilizing this method.