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

Quantum Electronics and Laser Science Conference

Formation of stable ultracold molecules by photoassociation with chirped laser pulses

Christiane P. Koch, Eliane Luc-Koenig, Françoise Masnou-Seeuws

Published Dec 10, 2005• 0 citations
Publisher

Abstract

We investigate photoassociation of ultracold atoms, such as Cs(6s), with chirped laser pulses in the ps range. Numerical calculations are analyzed, demonstrating efficient population inversion within a photoassociation window. Stabilization of the photoassociated molecules into bound levels of the ground state is discussed. Ongoing work on photoassociation of rubidium with femtosecond pulses will be presented at the conference.

DOI
10.1109/qels.2005.1548685

Related papers

Formation ofstable ultracold molecules byphotoassociation withchirped laser pulses

Christiane P. Koch, Eliane Luc-Koenig

Weinvestigate photoassociation ofultracold atoms, suchasCs(6s), withchirped laser pulses inthepsrange. Numerical calculations areanalyzed, demonstrating efficient popula- tion inversion within aphotoassociation window. Stabilization ofthephotoassociated molecules into boundlevels oftheground state isdiscussed. Ongoing workonphotoassociation ofrubidium withfemtosecond pulses will bepresented attheconference.

•Jan 1, 2005•0 citations

Photoassociation of cold atoms with chirped laser pulses: Time-dependent calculations and analysis of the adiabatic transfer within a two-state model

Eliane Luc-Koenig, Ronnie Kosloff, Françoise Masnou-Seeuws +1 more

This theoretical paper presents numerical calculations for the photoassociation of ultracold cesium atoms with a chirped laser pulse and a detailed analysis of the results. In contrast with earlier work, the initial state is represented by a stationary continuum wave function. In the chosen example, it is shown that an important population transfer is achieved to $\ensuremath{\approx}15$ vibrational levels in the vicinity of the $v=98$ bound level in the external well of the ${0}_{g}^{\ensuremath{-}}(6s+6{p}_{3∕2})$ potential. Such levels lie in the energy range swept by the instantaneous frequency of the pulse, thus defining a ``photoassociation window.'' Levels outside this window may be significantly excited during the pulse, but no population remains there after the pulse. Finally, the population transfer to the last vibrational levels of the ground $a\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\sum}_{u}^{+}(6\mathrm{s}+6\mathrm{s})$ state is significant, making stable molecules. The results are interpreted in the framework of a two-state model as an adiabatic inversion mechanism, efficient only within the photoassociation window. The large value found for the photoassociation rate suggests promising applications. The present chirp has been designed in view of creating in the excited state a vibrational wave packet that is focusing at the barrier of the double-well potential.

arXiv:physics/0404028•Physical Review A•Sep 27, 2004•107 citations

Making ultracold molecules in a two-color pump-dump photoassociation scheme using chirped pulses

Christiane P. Koch, Eliane Luc-Koenig, Françoise Masnou-Seeuws

This theoretical paper investigates the formation of ground state molecules from ultracold cesium atoms in a two-color scheme. Following previous work on photoassociation with chirped picosecond pulses [Luc-Koenig et al., Phys. Rev. A, 70, 033414 (2004)], we investigate stabilization by a second (dump) pulse. By appropriately choosing the dump pulse parameters and time delay with respect to the photoassociation pulse, we show that a large number of deeply bound molecules are created in the ground triplet state. We discuss (i) broad-bandwidth dump pulses which maximize the probability to form molecules while creating a broad vibrational distribution as well as (ii) narrow-bandwidth pulses populating a single vibrational ground state level, bound by $113\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$. The use of chirped pulses makes the two-color scheme robust, simple, and efficient.

arXiv:physics/0508090•Physical Review A•Mar 7, 2006•97 citations

Short-pulse photoassociation in rubidium below the D1 line

Christiane P. Koch, Ronnie Kosloff, Françoise Masnou-Seeuws

Photoassociation of two ultracold rubidium atoms and the subsequent formation of stable molecules in the singlet ground and lowest triplet states is investigated theoretically. The method employs laser pulses inducing transitions via excited states correlated to the $5S+5{P}_{1∕2}$ asymptote. Weakly bound molecules in the singlet ground or lowest triplet state can be created by a single pulse while the formation of more deeply bound molecules requires a two-color pump-dump scenario. More deeply bound molecules in the singlet ground or lowest triplet state can be produced only if efficient mechanisms for both pump and dump steps exist. While long-range $1∕{R}^{3}$ potentials allow for efficient photoassociation, stabilization is facilitated by the resonant spin-orbit coupling of the ${0}_{u}^{+}$ states. Molecules in the singlet ground state bound by a few wave numbers can thus be formed. This provides a promising first step toward ground-state molecules which are ultracold in both translational and vibrational degrees of freedom.

arXiv:physics/0511235•Physical Review A•Apr 13, 2006•73 citations

Making Ultracold Molecules from Ultracold Atoms with Chirped Laser Pulses

Elaine Luc-Koenig, Christiane P. Koch, Ronnie Kosloff +1 more

The possibility to use chirped laser pulses to optimize the formation of ultracold moleculesby photoassociation and radiative stabilization is discussed. Calculations of the absolute number of molecules per pulse has been performed for Rb2 and Cs2. Article not available.

Frontiers in Optics•Jan 1, 2006•0 citations

FORMATION OF ULTRACOLD CESIUM MOLECULES IN THE GROUND ELECTRONIC STATE

Xue‐Jin Hu, Wei Zhang, Yin Hui Huang +2 more

We investigate theoretically the preparation of ultracold photoassociated Cs 2 molecules in the lowest vibrational level of the ground electronic state via the stimulated Raman adiabatic passage (STIRAP) by solving the time-dependent Schrödinger equation using the mapped Fourier grid method. A negative chirped laser pulse is used to produce the unstable photoassociated molecules in the excited electronic state. A dump pulse is utilized to transfer a partial population of the unstable photoassociated molecules to the vibrational v″ = 18 level of the ground electronic state. This part of population is then transferred to the v″ = 0 level of the ground electronic state by the pump and Stokes laser pulses via an intermediate state which is taken to be the v′ = 7 level of the excited electronic state, forming the stable photoassociated molecules. The population transfer efficiency from v″ = 18 to v″ = 0 in the ground electronic state reaches 96.2% via the STIRAP.

Journal of Theoretical and Computational Chemistry•Dec 1, 2012•7 citations
We investigate photoassociation of ultracold atoms, such as Cs(6s), with chirped laser pulses in the ps range. Numerical calculations are analyzed, demonstrating efficient population inversion within a photoassociation window. Stabilization of the photoassociated molecules into bound levels of the ground state is discussed. Ongoing work on photoassociation of rubidium with femtosecond pulses will be presented at the conference.
This theoretical paper presents numerical calculations for the photoassociation of ultracold cesium atoms with a chirped laser pulse and a detailed analysis of the results. In contrast with earlier work, the initial state is represented by a stationary continuum wave function. In the chosen example, it is shown that an important population transfer is achieved to $\ensuremath{\approx}15$ vibrational levels in the vicinity of the v=98v=98v=98 bound level in the external well of the ${0}_{g}^{\ensuremath{-}}(6s+6{p}_{3∕2})$ potential. Such levels lie in the energy range swept by the instantaneous frequency of the pulse, thus defining a ``photoassociation window.'' Levels outside this window may be significantly excited during the pulse, but no population remains there after the pulse. Finally, the population transfer to the last vibrational levels of the ground $a\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\sum}_{u}^{+}(6\mathrm{s}+6\mathrm{s})$ state is significant, making stable molecules. The results are interpreted in the framework of a two-state model as an adiabatic inversion mechanism, efficient only within the photoassociation window. The large value found for the photoassociation rate suggests promising applications. The present chirp has been designed in view of creating in the excited state a vibrational wave packet that is focusing at the barrier of the double-well potential.
This theoretical paper investigates the formation of ground state molecules from ultracold cesium atoms in a two-color scheme. Following previous work on photoassociation with chirped picosecond pulses [Luc-Koenig et al., Phys. Rev. A, 70, 033414 (2004)], we investigate stabilization by a second (dump) pulse. By appropriately choosing the dump pulse parameters and time delay with respect to the photoassociation pulse, we show that a large number of deeply bound molecules are created in the ground triplet state. We discuss (i) broad-bandwidth dump pulses which maximize the probability to form molecules while creating a broad vibrational distribution as well as (ii) narrow-bandwidth pulses populating a single vibrational ground state level, bound by $113\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$. The use of chirped pulses makes the two-color scheme robust, simple, and efficient.
Photoassociation of two ultracold rubidium atoms and the subsequent formation of stable molecules in the singlet ground and lowest triplet states is investigated theoretically. The method employs laser pulses inducing transitions via excited states correlated to the 5S+5P1∕25S+5{P}_{1∕2}5S+5P1∕2​ asymptote. Weakly bound molecules in the singlet ground or lowest triplet state can be created by a single pulse while the formation of more deeply bound molecules requires a two-color pump-dump scenario. More deeply bound molecules in the singlet ground or lowest triplet state can be produced only if efficient mechanisms for both pump and dump steps exist. While long-range 1∕R31∕{R}^{3}1∕R3 potentials allow for efficient photoassociation, stabilization is facilitated by the resonant spin-orbit coupling of the 0u+{0}_{u}^{+}0u+​ states. Molecules in the singlet ground state bound by a few wave numbers can thus be formed. This provides a promising first step toward ground-state molecules which are ultracold in both translational and vibrational degrees of freedom.
We investigate theoretically the preparation of ultracold photoassociated Cs 2 molecules in the lowest vibrational level of the ground electronic state via the stimulated Raman adiabatic passage (STIRAP) by solving the time-dependent Schrödinger equation using the mapped Fourier grid method. A negative chirped laser pulse is used to produce the unstable photoassociated molecules in the excited electronic state. A dump pulse is utilized to transfer a partial population of the unstable photoassociated molecules to the vibrational v″ = 18 level of the ground electronic state. This part of population is then transferred to the v″ = 0 level of the ground electronic state by the pump and Stokes laser pulses via an intermediate state which is taken to be the v′ = 7 level of the excited electronic state, forming the stable photoassociated molecules. The population transfer efficiency from v″ = 18 to v″ = 0 in the ground electronic state reaches 96.2% via the STIRAP.