Progress on direct photoassociation of halo molecules in ultracold $^{86}$ SrProgress on direct photoassociation of halo molecules in ultracold $^{86}$Sr

James Aman, Joshua C. Hill, Roger Ding +2 more

Bulletin of the American Physical SocietyMay 30, 20180 citations

Photoassociative spectroscopy of a halo molecule in Sr86

J. A. Aman, Joshua C. Hill, Roger Ding +3 more

Halo ${}^{86}$ Sr ${}_{2}$ molecules are photoassociated in their ground electronic state. The large sensitivity of the molecular binding energy to the near-resonant light suggests the possibility of probing naturally occurring Efimov states by optical means.Halo ${}^{86}$Sr${}_{2}$ molecules are photoassociated in their ground electronic state. The large sensitivity of the molecular binding energy to the near-resonant light suggests the possibility of probing naturally occurring Efimov states by optical means.

arXiv:1809.09267Physical Review ANov 28, 20189 citations

Ultracold Molecule Formation by Photoassociation

Edward E. Eyler, William C. Stwalley, P. L. Gould

CRC Press eBooksJun 25, 20091 citation

Two-photon photoassociative spectroscopy of strontium-86

James Aman

This dissertation describes two-photon photoassociation to the least-bound vibrational level of the X $^1\Sigma_g^+$ electronic ground state of the $^{86}$ Sr $_2$ dimer, which represents the first observation of this naturally occurring halo molecule. We measure the binding energy of this state to be $E_b=83.00(7)(20)$ \,kHz. Using the precise determination of the halo state binding energy and the universal theory for a very weakly-bound state on a potential that asymptotes to a van der Waals form, we determine $s$ -wave scattering lengths for all strontium isotopes. Our results are consistent with, but substantially more accurate than the previously determined values found from spectroscopic determination of long-range coefficients using other strontium isotopes. With a radial expectation value of $\langle r \rangle \approx 21$ \,nm the halo state extends well into the classically forbidden region, which results in a large sensitivity of the dimer binding energy to light near-resonant with a bound-bound transition on the metastable $^1S_0-{^3P_1}$ potential. This suggests that $^{86}$ Sr may be a promising candidate for manipulating atomic interactions via optical coupling of the molecular bound states and for probing naturally occurring Efimov states. Furthermore, we observe novel multi-photon spectral loss features due to strong coupling and small detuning of the photoassociation lasers. Numerical simulations of a simple three-level model undergoing a simultaneous two-frequency drive, shows that solutions of the time-dependent Schr\"{o}dinger equation accurately reproduce these additional loss features. A Floquet analysis of this model, yields analytic formulas for predicting the AC Stark shift of the halo molecule. Additionally, we report on the current state and recent modifications of our ultracold neutral strontium apparatus with a particular emphasis on the installation of a $532$ \,nm optical lattice. Characterization of this laser system and applications are discussed for further investigation of the strontium- $86$ halo molecule and additional photoassociation experiments.This dissertation describes two-photon photoassociation to the least-bound vibrational level of the X$^1\Sigma_g^+$ electronic ground state of the $^{86}$Sr$_2$ dimer, which represents the first observation of this naturally occurring halo molecule. We measure the binding energy of this state to be $E_b=83.00(7)(20)$\,kHz. Using the precise determination of the halo state binding energy and the universal theory for a very weakly-bound state on a potential that asymptotes to a van der Waals form, we determine $s$-wave scattering lengths for all strontium isotopes. Our results are consistent with, but substantially more accurate than the previously determined values found from spectroscopic determination of long-range coefficients using other strontium isotopes. With a radial expectation value of $\langle r \rangle \approx 21$\,nm the halo state extends well into the classically forbidden region, which results in a large sensitivity of the dimer binding energy to light near-resonant with a bound-bound transition on the metastable $^1S_0-{^3P_1}$ potential. This suggests that $^{86}$Sr may be a promising candidate for manipulating atomic interactions via optical coupling of the molecular bound states and for probing naturally occurring Efimov states. Furthermore, we observe novel multi-photon spectral loss features due to strong coupling and small detuning of the photoassociation lasers. Numerical simulations of a simple three-level model undergoing a simultaneous two-frequency drive, shows that solutions of the time-dependent Schr\"{o}dinger equation accurately reproduce these additional loss features. A Floquet analysis of this model, yields analytic formulas for predicting the AC Stark shift of the halo molecule. Additionally, we report on the current state and recent modifications of our ultracold neutral strontium apparatus with a particular emphasis on the installation of a $532$\,nm optical lattice. Characterization of this laser system and applications are discussed for further investigation of the strontium-$86$ halo molecule and additional photoassociation experiments.

Sep 6, 20190 citations

Molecular Photoassociation and Ultracold Molecules

P. Pillet, Françoise Masnou-Seeuws, A. Crubellier

Springer eBooksJan 1, 20013 citations

Creation and precise spectroscopy of $^{86}$ Sr $_2$ halo moleculesCreation and precise spectroscopy of $^{86}$Sr$_2$ halo molecules

Brandon Iritani, Jingjing Huang, Wenwei Xu +3 more

We report on the creation of $^{86}$ Sr $_2$ molecules in the halo state and neighboring weakly bound states. Efficient molecule production via one-photon photoassociation relies on sufficient wavefunction overlap between the target vibrational states in the electronic excited- and ground-state potentials. Using Autler-Townes spectroscopy, transition strengths are measured to identify optimal pathways for production of weakly bound molecules. Vibrational splittings for the three least-bound vibrational states are measured, and dominant systematic uncertainties are evaluated with uncertainties below 100 Hz. From these splittings, absolute binding energies for these weakly bound vibrational states are determined. The results pave the way to a molecular isotope shift measurement with Sr $_2$ .We report on the creation of $^{86}$Sr$_2$ molecules in the halo state and neighboring weakly bound states. Efficient molecule production via one-photon photoassociation relies on sufficient wavefunction overlap between the target vibrational states in the electronic excited- and ground-state potentials. Using Autler-Townes spectroscopy, transition strengths are measured to identify optimal pathways for production of weakly bound molecules. Vibrational splittings for the three least-bound vibrational states are measured, and dominant systematic uncertainties are evaluated with uncertainties below 100 Hz. From these splittings, absolute binding energies for these weakly bound vibrational states are determined. The results pave the way to a molecular isotope shift measurement with Sr$_2$.

physics.atom-phCross-listedarXiv:2601.06319Physical Review ResearchJan 13, 20260 citations

Progress on direct photoassociation of halo molecules in ultracold

^{86}

Halo

{}^{86}

{}_{2}

molecules are photoassociated in their ground electronic state. The large sensitivity of the molecular binding energy to the near-resonant light suggests the possibility of probing naturally occurring Efimov states by optical means.

This dissertation describes two-photon photoassociation to the least-bound vibrational level of the X

^1\Sigma_g^+

electronic ground state of the

^{86}

_2

dimer, which represents the first observation of this naturally occurring halo molecule. We measure the binding energy of this state to be

E_b=83.00(7)(20)

\,kHz. Using the precise determination of the halo state binding energy and the universal theory for a very weakly-bound state on a potential that asymptotes to a van der Waals form, we determine

s

-wave scattering lengths for all strontium isotopes. Our results are consistent with, but substantially more accurate than the previously determined values found from spectroscopic determination of long-range coefficients using other strontium isotopes. With a radial expectation value of

\langle r \rangle \approx 21

\,nm the halo state extends well into the classically forbidden region, which results in a large sensitivity of the dimer binding energy to light near-resonant with a bound-bound transition on the metastable

^1S_0-{^3P_1}

potential. This suggests that

^{86}

Sr may be a promising candidate for manipulating atomic interactions via optical coupling of the molecular bound states and for probing naturally occurring Efimov states. Furthermore, we observe novel multi-photon spectral loss features due to strong coupling and small detuning of the photoassociation lasers. Numerical simulations of a simple three-level model undergoing a simultaneous two-frequency drive, shows that solutions of the time-dependent Schr\"{o}dinger equation accurately reproduce these additional loss features. A Floquet analysis of this model, yields analytic formulas for predicting the AC Stark shift of the halo molecule. Additionally, we report on the current state and recent modifications of our ultracold neutral strontium apparatus with a particular emphasis on the installation of a

532

\,nm optical lattice. Characterization of this laser system and applications are discussed for further investigation of the strontium-

86

halo molecule and additional photoassociation experiments.

Creation and precise spectroscopy of

^{86}

_2

halo molecules

We report on the creation of

^{86}

_2

molecules in the halo state and neighboring weakly bound states. Efficient molecule production via one-photon photoassociation relies on sufficient wavefunction overlap between the target vibrational states in the electronic excited- and ground-state potentials. Using Autler-Townes spectroscopy, transition strengths are measured to identify optimal pathways for production of weakly bound molecules. Vibrational splittings for the three least-bound vibrational states are measured, and dominant systematic uncertainties are evaluated with uncertainties below 100 Hz. From these splittings, absolute binding energies for these weakly bound vibrational states are determined. The results pave the way to a molecular isotope shift measurement with Sr

_2