Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1912.09364 · Physical Review Research

Prospects for laser cooling of polyatomic molecules with increasing complexity

Jacek Kłos, Svetlana Kotochigova

Published Mar 31, 2020• 47 citations
arXivHTMLPDF

Abstract

The authors discuss prospects for laser cooling of polyatomic molecules of increasing complexity from expanding alkaline chains to exohedral and endohedral fullerenes with one or two optical cycling centers attached. They demonstrate the degree to which these cycling centers retain their beneficial photon scattering properties for a diverse list of molecules. Their computational results indicate that a second optical cycling center potentially doubles the photon scattering rate and, therefore, improves the efficiency of the laser-cooling process.

DOI
10.1103/physrevresearch.2.013384

Related papers

Proposal for Laser Cooling of Complex Polyatomic Molecules

Ivan Kozyryev, Louis Baum, Kyle Matsuda +1 more

An experimentally feasible strategy for direct laser cooling of polyatomic molecules with six or more atoms is presented. Our approach relies on the attachment of a metal atom to a complex molecule, where it acts as an active photon cycling site. We describe a laser cooling scheme for alkaline earth monoalkoxide free radicals taking advantage of the phase space compression of a cryogenic buffer-gas beam. Possible applications are presented including laser cooling of chiral molecules and slowing of molecular beams using coherent photon processes.

ChemPhysChem•Oct 19, 2016•113 citations

Toward Ultracold Organic Chemistry: Prospects of Laser Cooling Large Organic Molecules

Maxim V. Ivanov, Felix H. Bangerter, Paweł Wójcik +1 more

Ultracold organic chemistry enables studies of reaction dynamics and mechanisms in the quantum regime. Access to ultracold molecules hinges on the ability to efficiently scatter multiple photons via quasi-closed cycling transitions. Optical cycling in polyatomic molecules is challenging due to their complex electronic structure. Using equation-of-motion coupled-cluster calculations, we demonstrate that an alkaline earth metal attached to various aromatic ligands (such as benzene, phenol, cyclopentadienyl, and pyrrolide) offers nearly closed cycling transitions with only a few additional repump lasers. We also show that aromatic ligands such as benzene can accommodate multiple cycling centers in various geometrical arrangements, opening new avenues in quantum information science, precision measurements, and ultracold chemistry.

The Journal of Physical Chemistry Letters•Jul 27, 2020•42 citations

Dual Optical Cycling Centers Mounted on an Organic Scaffold: New Insights from Quantum Chemistry Calculations and Symmetry Analysis

Taras A. Khvorost, Paweł Wójcik, Cecilia Chang +6 more

Molecules cooled to ultracold temperatures are desirable for applications in fundamental physics and quantum information science. However, cooling polyatomic molecules with more than six atoms has not yet been achieved. Building on the idea of an optical cycling center (OCC), a moiety supporting a set of localized and isolated electronic states within a polyatomic molecule, molecules with two OCCs (bi-OCCs) may afford better cooling efficiency by doubling the photon scattering rate. By using quantum chemistry calculations, we assess the extent of the coupling of the two OCCs with each other and the molecular scaffold. We show that promising coolable bi-OCC molecules can be proposed by following chemical design principles.

The Journal of Physical Chemistry Letters•May 20, 2024•12 citations

Molecular Asymmetry and Optical Cycling: Laser Cooling Asymmetric Top Molecules

Benjamin L. Augenbraun, John M. Doyle, Tanya Zelevinsky +1 more

We present a practical roadmap to achieve optical cycling and laser cooling of asymmetric top molecules (ATMs).Our theoretical analysis describes how reduced molecular symmetry, as compared to diatomic and symmetric nonlinear molecules, plays a role in photon scattering.We present methods to circumvent limitations on rapid photon cycling in these systems.We calculate vibrational branching ratios for a diverse set of asymmetric top molecules and find that many species within a broad class of molecules can be effectively cooled with a manageable number of lasers.We also describe methods to achieve rotationally closed optical cycles in ATMs.Despite significant structural complexity, laser cooling can be made effective by using extensions of the current techniques for linear molecules.Potential scientific impacts of laser-cooled ATMs span frontiers in controlled chemistry, quantum simulation, and searches for physics beyond the Standard Model.

arXiv:2001.11020•Physical Review X•Jul 29, 2020•80 citations

Multivalent optical cycling centers: towards control of polyatomics with multi-electron degrees of freedom

Phelan Yu, Adrian Lopez, William A. Goddard +1 more

quantum chemical methods. Despite increased internal complexity and challenging design parameters, we find several molecules possessing quasi-closed photon cycling schemes with highly diagonal, visible and near-infrared transitions. Furthermore, we identify new heuristics for engineering optically controllable and laser-coolable polyatomic molecules with multi-electron cycling centers. Our results help elucidate the interplay between hybridization, repulsion, and ionicity in optically active species and provide new directions for using polyatomic molecules with complex electronic structure as a resource for quantum science and measurement.

arXiv:2205.11860•Physical Chemistry Chemical Physics•Nov 29, 2022•8 citations

Large molasses-like cooling forces for molecules using polychromatic optical fields: A theoretical description

Konrad Wenz, Ivan Kozyryev, Rees L. McNally +2 more

Recent theoretical investigations have indicated that rapid optical cycling should be feasible in complex polyatomic molecules with diverse constituents, geometries, and symmetries.However, as a composite molecular mass grows, so does the required number of photon scattering events necessary to decelerate and confine molecular beams using laser light.Utilizing coherent momentum exchange between light fields and molecules can suppress spontaneous emission and significantly reduce experimental complexity for slowing and trapping.Working with BaH as a test species, we have identified a robust, experimentally viable configuration to achieve large molasses-like cooling forces for molecules using polychromatic optical fields addressing both X -A and X -B electronic transitions, simultaneously.Using numerical solutions of the time-dependent density matrix as well as Monte Carlo simulations, we demonstrate that creation of suppressed emission rate (SupER) molasses with large capture velocities (∼40 m/s) is generically feasible for polyatomic molecules of increasing complexity that have an optical cycling center.Proposed SupER molasses are anticipated to not only extend quantum control to novel molecular species with abundant vibrational decay channels, but also significantly increase trapped densities for previously laser-cooled diatomic and triatomic species.

arXiv:2007.01776•Physical Review Research•Dec 15, 2020•17 citations
The authors discuss prospects for laser cooling of polyatomic molecules of increasing complexity from expanding alkaline chains to exohedral and endohedral fullerenes with one or two optical cycling centers attached. They demonstrate the degree to which these cycling centers retain their beneficial photon scattering properties for a diverse list of molecules. Their computational results indicate that a second optical cycling center potentially doubles the photon scattering rate and, therefore, improves the efficiency of the laser-cooling process.
An experimentally feasible strategy for direct laser cooling of polyatomic molecules with six or more atoms is presented. Our approach relies on the attachment of a metal atom to a complex molecule, where it acts as an active photon cycling site. We describe a laser cooling scheme for alkaline earth monoalkoxide free radicals taking advantage of the phase space compression of a cryogenic buffer-gas beam. Possible applications are presented including laser cooling of chiral molecules and slowing of molecular beams using coherent photon processes.
Ultracold organic chemistry enables studies of reaction dynamics and mechanisms in the quantum regime. Access to ultracold molecules hinges on the ability to efficiently scatter multiple photons via quasi-closed cycling transitions. Optical cycling in polyatomic molecules is challenging due to their complex electronic structure. Using equation-of-motion coupled-cluster calculations, we demonstrate that an alkaline earth metal attached to various aromatic ligands (such as benzene, phenol, cyclopentadienyl, and pyrrolide) offers nearly closed cycling transitions with only a few additional repump lasers. We also show that aromatic ligands such as benzene can accommodate multiple cycling centers in various geometrical arrangements, opening new avenues in quantum information science, precision measurements, and ultracold chemistry.
Molecules cooled to ultracold temperatures are desirable for applications in fundamental physics and quantum information science. However, cooling polyatomic molecules with more than six atoms has not yet been achieved. Building on the idea of an optical cycling center (OCC), a moiety supporting a set of localized and isolated electronic states within a polyatomic molecule, molecules with two OCCs (bi-OCCs) may afford better cooling efficiency by doubling the photon scattering rate. By using quantum chemistry calculations, we assess the extent of the coupling of the two OCCs with each other and the molecular scaffold. We show that promising coolable bi-OCC molecules can be proposed by following chemical design principles.
We present a practical roadmap to achieve optical cycling and laser cooling of asymmetric top molecules (ATMs).Our theoretical analysis describes how reduced molecular symmetry, as compared to diatomic and symmetric nonlinear molecules, plays a role in photon scattering.We present methods to circumvent limitations on rapid photon cycling in these systems.We calculate vibrational branching ratios for a diverse set of asymmetric top molecules and find that many species within a broad class of molecules can be effectively cooled with a manageable number of lasers.We also describe methods to achieve rotationally closed optical cycles in ATMs.Despite significant structural complexity, laser cooling can be made effective by using extensions of the current techniques for linear molecules.Potential scientific impacts of laser-cooled ATMs span frontiers in controlled chemistry, quantum simulation, and searches for physics beyond the Standard Model.
quantum chemical methods. Despite increased internal complexity and challenging design parameters, we find several molecules possessing quasi-closed photon cycling schemes with highly diagonal, visible and near-infrared transitions. Furthermore, we identify new heuristics for engineering optically controllable and laser-coolable polyatomic molecules with multi-electron cycling centers. Our results help elucidate the interplay between hybridization, repulsion, and ionicity in optically active species and provide new directions for using polyatomic molecules with complex electronic structure as a resource for quantum science and measurement.
Recent theoretical investigations have indicated that rapid optical cycling should be feasible in complex polyatomic molecules with diverse constituents, geometries, and symmetries.However, as a composite molecular mass grows, so does the required number of photon scattering events necessary to decelerate and confine molecular beams using laser light.Utilizing coherent momentum exchange between light fields and molecules can suppress spontaneous emission and significantly reduce experimental complexity for slowing and trapping.Working with BaH as a test species, we have identified a robust, experimentally viable configuration to achieve large molasses-like cooling forces for molecules using polychromatic optical fields addressing both X -A and X -B electronic transitions, simultaneously.Using numerical solutions of the time-dependent density matrix as well as Monte Carlo simulations, we demonstrate that creation of suppressed emission rate (SupER) molasses with large capture velocities (∼40 m/s) is generically feasible for polyatomic molecules of increasing complexity that have an optical cycling center.Proposed SupER molasses are anticipated to not only extend quantum control to novel molecular species with abundant vibrational decay channels, but also significantly increase trapped densities for previously laser-cooled diatomic and triatomic species.