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

Physics

Potassium atoms feel a distant attraction

Anonymous

Published Jul 28, 2008• 0 citations
Publisher

Abstract

The atoms in highly excited vibrational states of a diatomic molecule can be quite far apart near their maximum excursion. Physicists are now using laser spectroscopy to carefully measure the long-range effective interaction between potassium atoms in these states—an essential parameter to understanding ultracold atomic collisions.
DOI
10.1103/physics.1.s11

Related papers

Polarization spectroscopy and laser-locking for excitation of ultracold potassium atoms

C. W. S. Conover, Max Eberhart, Philip Adamson

Bulletin of the American Physical Society•May 24, 2016•0 citations

Production of ultracold potassium molecules and development of high sensitivity spectroscopic methods

Anguel Nikolov

In the first part of this dissertation we develop and successfully demonstrate two methods, based on photoassociation of ultracold potassium atoms, for producing ultracold K2 molecules, with sub mK temperatures, in deeply bound vibrational levels of the ground XS+g 1 state. The principal objective has been to develop an “ultracold molecule factory” that can be used to support experiments on spectroscopy, collisions, and chemistry of ultracold molecules. ^ In the first experiment the ground-state molecules are produced by the radiative decay of excited, n≅191 AS+u 1 state molecules, photoassociated from ultracold potassium atoms in a vapor-cell MOT. The decay is primarily into the vibrational continuum, but a small fraction decays into bound levels of the X state near n = 36. The experimentally observed molecule production rate is about 103 per second. ^ In our second experiment, we use two-step laser excitation to effect an “R-transfer” from long-range to intermediate internuclear separations, greatly increasing the efficiency for radiative production of low- n molecules in the X state. Molecules are formed in the Pg1 state by photoassociation, then excited by a second laser to the 51Pu or 61Pu Rydberg states, in selected vibrational levels from n = 13–18. Finally, radiative decay produces very large numbers of X state molecules with n≅25 and significant numbers of molecules in very low vibrational levels, including n = 0. We have observed production rates up to about 105 molecules/second per vibrational level. ^ In both experiments the ground-state molecules are detected with a sensitive and selective resonant two-color photoionization with nanosecond pulses. ^ In the second part of this dissertation we demonstrate a novel method for high sensitivity absorption measurements, that combines a phase modulated, high-resolution pulsed laser with an actively stabilized optical cavity to achieve a sensitivity of ∼10−9 per cm. This is comparable to the best existing methods for pulsed absorption measurements, but unlike most other methods, it can also be readily extended to the UV region and to Doppler-free spectroscopy. ^

•Oct 1, 2000•0 citations

Molecular Resonances due to Long-Range Interactions between Ultracold Rydberg Atoms

D. Tong, S. M. Farooqi, Jovica Stanojevic +2 more

Bulletin of the American Physical Society•May 18, 2005•0 citations

Ultracold photoassociative spectroscopy of heteronuclear alkali-metal diatomic molecules

He Wang, William C. Stwalley

We have examined and identified the excited long-range Hund’s case (c) molecular states of the ten heteronuclear alkali metal diatomic molecules which support bound states and can be probed by ultracold photoassociative spectroscopy. Analytical expressions for the heteronuclear long-range free-bound Franck–Condon factors as a function of the internuclear distance R and the vibrational quantum number v are derived and discussed. The KRb system has considerably stronger excited long-range interactions than any other heteronuclear alkali diatomic molecule and has very favorable Franck–Condon factors for the photoassociation process. The heteronuclear photoassociative spectroscopy will provide spectroscopic measurements of the binary elastic scattering lengths of heteronuclear cold collisions which are the crucial parameters for sympathetic cooling of mixed atomic gases.

The Journal of Chemical Physics•Apr 8, 1998•123 citations

Ultracold collisions between atoms and molecules in high vibrational states: effect of the atom-atom scattering length

Goulven Quéméner, Pascal Honvault, Jean–Michel Launay

Bulletin of the American Physical Society•May 30, 2008•0 citations

Efficient production and spectroscopy of ultracold potassium molecules in the electronic ground state

J. R. Ensher, Anguel Nikolov, Edward E. Eyler +3 more

Summary form only given. We report results from an efficient new method for producing translationally cold (T<1 mK) potassium molecules in the ground X/sup 1//spl Sigma//sub g//sup +/ electronic state. We use the two-photon R-transfer scheme conceptually similar to a proposal by Band and Julienne (1995). First, ultracold potassium atoms in a MOT are photoassociated at long range to the 1/sub g/ molecular electronic state, which correlates to the 1/sup 1//spl Pi//sub g/ state at short range. The resulting molecules are then excited with a second laser to the 5/sup 1//spl Pi//sub u/ or 6/sup 1//spl Pi//sub u/ Rydberg states. These Rydberg states have favorable Franck-Condon factors for spontaneous decay into low vibrational levels of the ground state. The molecules are detected by use of two-color resonant ionization with pulsed lasers. By scanning one of the detection lasers, we observe transitions from several vibrational levels of the X state. The largest observed molecule formation rate in a single vibrational level is about 10/sup 5/ molecules/s for /spl nu/=25. Molecules in the lowest vibrational levels, including /spl nu/=0, are also observed with slightly lower rates of production. The translational temperature of the ground-state molecules is measured by analyzing their ballistic decay from the detection region. It is approximately 500 /spl mu/K, roughly the same as the estimated temperature of potassium atoms in the MOT.

Quantum Electronics and Laser Science Conference•May 12, 2000•0 citations
In the first part of this dissertation we develop and successfully demonstrate two methods, based on photoassociation of ultracold potassium atoms, for producing ultracold K2 molecules, with sub mK temperatures, in deeply bound vibrational levels of the ground XS+g 1 state. The principal objective has been to develop an “ultracold molecule factory” that can be used to support experiments on spectroscopy, collisions, and chemistry of ultracold molecules. ^ In the first experiment the ground-state molecules are produced by the radiative decay of excited, n≅191 AS+u 1 state molecules, photoassociated from ultracold potassium atoms in a vapor-cell MOT. The decay is primarily into the vibrational continuum, but a small fraction decays into bound levels of the X state near n = 36. The experimentally observed molecule production rate is about 103 per second. ^ In our second experiment, we use two-step laser excitation to effect an “R-transfer” from long-range to intermediate internuclear separations, greatly increasing the efficiency for radiative production of low- n molecules in the X state. Molecules are formed in the Pg1 state by photoassociation, then excited by a second laser to the 51Pu or 61Pu Rydberg states, in selected vibrational levels from n = 13–18. Finally, radiative decay produces very large numbers of X state molecules with n≅25 and significant numbers of molecules in very low vibrational levels, including n = 0. We have observed production rates up to about 105 molecules/second per vibrational level. ^ In both experiments the ground-state molecules are detected with a sensitive and selective resonant two-color photoionization with nanosecond pulses. ^ In the second part of this dissertation we demonstrate a novel method for high sensitivity absorption measurements, that combines a phase modulated, high-resolution pulsed laser with an actively stabilized optical cavity to achieve a sensitivity of ∼10−9 per cm. This is comparable to the best existing methods for pulsed absorption measurements, but unlike most other methods, it can also be readily extended to the UV region and to Doppler-free spectroscopy. ^
We have examined and identified the excited long-range Hund’s case (c) molecular states of the ten heteronuclear alkali metal diatomic molecules which support bound states and can be probed by ultracold photoassociative spectroscopy. Analytical expressions for the heteronuclear long-range free-bound Franck–Condon factors as a function of the internuclear distance R and the vibrational quantum number v are derived and discussed. The KRb system has considerably stronger excited long-range interactions than any other heteronuclear alkali diatomic molecule and has very favorable Franck–Condon factors for the photoassociation process. The heteronuclear photoassociative spectroscopy will provide spectroscopic measurements of the binary elastic scattering lengths of heteronuclear cold collisions which are the crucial parameters for sympathetic cooling of mixed atomic gases.
Summary form only given. We report results from an efficient new method for producing translationally cold (T<1 mK) potassium molecules in the ground X/sup 1//spl Sigma//sub g//sup +/ electronic state. We use the two-photon R-transfer scheme conceptually similar to a proposal by Band and Julienne (1995). First, ultracold potassium atoms in a MOT are photoassociated at long range to the 1/sub g/ molecular electronic state, which correlates to the 1/sup 1//spl Pi//sub g/ state at short range. The resulting molecules are then excited with a second laser to the 5/sup 1//spl Pi//sub u/ or 6/sup 1//spl Pi//sub u/ Rydberg states. These Rydberg states have favorable Franck-Condon factors for spontaneous decay into low vibrational levels of the ground state. The molecules are detected by use of two-color resonant ionization with pulsed lasers. By scanning one of the detection lasers, we observe transitions from several vibrational levels of the X state. The largest observed molecule formation rate in a single vibrational level is about 10/sup 5/ molecules/s for /spl nu/=25. Molecules in the lowest vibrational levels, including /spl nu/=0, are also observed with slightly lower rates of production. The translational temperature of the ground-state molecules is measured by analyzing their ballistic decay from the detection region. It is approximately 500 /spl mu/K, roughly the same as the estimated temperature of potassium atoms in the MOT.