William C. Stwalley

Mass‐reduced quantum numbers: Application to the isotopic mercury hydrides

The concept of mass‐reduced quantum numbers is introduced and discussed. For a diatomic molecule, the mass‐reduced vibrational quantum number η= (v+1/2)/(μ)1/2 and mass‐reduced rotational quantum number ξ=J (J+1)/μ are used and exemplified. Isotopically combined methods of potential determination from spectroscopic data follow from introduction of these quantum numbers, e.g., the isotopically combined Rydberg–Klein–Rees (RKR) method. These concepts are applied in detail to the isotopic mercury hydrides. It is shown that mass‐reduced functions exist which accurately describe, for example, vibrational spacings [ΔG (η)(=dG/dη) = μ1/2ΔG (v+1/2)], rotational constants [B (η) =dE (η,ξ)/ dξ=μB (v)], and centrifugal distortion constants [D (η) =μ2D (v)]. The vibrational and rotational mass‐reduced functions are used to construct an isotopically combined RKR potential. This potential, when joined to the long‐range potential and extrapolated at short range reproduces the energy levels fairly well. In a companion pa...

Cold molecules: theory, experiment, applications

COLD COLLISONS Theory of Cold Atomic and Molecular Collisions, J.M. Hutson Electric Dipoles at Ultralow Temperatures, J.L. Bohn Inelastic Collisions and Chemical Reactions of Molecules at Ultracold Temperatures, G. Quemener, N. Balakrishnan and A. Dalgarno Effects of External Electromagnetic Fields on Collisions of Molecules at Low Temperatures, T.V. Tscherbul and R.V. Krems PHOTOASSOCIATION Ultracold Molecule Formation by Photoassociation, W.C. Stwalley, P.L. Gould, and E.E. Eyler Molecular States Near a Collision Threshold, P.S. Julienne Prospects for Control of Ultracold Molecule Formation via Photoassociation with Chirped Laser Pulses, E. Luc-Koenig and F. Masnou-Seeuws Adiabatic Raman Photoassociation with Shaped Laser Pulses, E.A. Shapiro and M. Shapiro FEW- AND MANY-BODY PHYSICS Ultracold Feshbach Molecules, F. Ferlaino, S. Knoop, and R. Grimm Molecular Regimes in Ultracold Fermi Gases, D.S. Petrov, C. Salomon, and G.V. Shlyapnikov Theory of Ultracold Feshbach Molecules, T.M. Hanna, H. Martay and T. Kohler Condensed Matter Physics with Cold Polar Molecules, G. Pupillo, A. Micheli, H.P. Buchler, and P. Zoller COOLING AND TRAPPING Cooling, Trap Loading, and Beam Production Using a Cryogenic Helium Buffer Gas, W.C. Campbell and J.M. Doyle Slowing, Trapping, and Storing of Polar Molecules by Means of Electric Fields, S.Y.T. van de Meerakker, H.L. Bethlem, and G. Meijer TESTS OF FUNDAMENTAL LAWS Preparation and Manipulation of Molecules for Fundamental Physics Tests, M.R. Tarbutt, J.J. Hudson, B.E. Sauer, and E.A. Hinds Variation of the Fundamental Constants as Revealed by Molecules: Astrophysical Observations and Laboratory Experiments, V.V. Flambaum and M.G. Kozlov QUANTUM COMPUTING Quantum Information Processing with Ultracold Polar Molecules, S.F. Yelin, D. DeMille, and R. Cote COLD MOLECULAR IONS Sympathetically Cooled Molecular Ions: From Principles to First Applications, B. Roth and S. Schiller Index

First observation of bound–continuum transitions in the laser‐induced A 1Σ+u–X 1Σ+g fluorescence of Na2

We report an interesting spectrum of Na2 excited by a Kr+ (5682 A) laser which shows a long series of R–P doublets in the region 5600–8000 A and a continuum with three very broad maxima beyond 8000 A. Our spectral analysis reveals that the laser populates the v′=34, J′=50 level in the A1Σ+u state from where Na2 molecules fluoresce not only to the bound vibrational levels of the entire ground state potential well (3≤v″≤56) but also to the continuum levels above the well. We have made an independent theoretical quantitative prediction of the continuous emission and the agreement between experiment and theory is found to be excellent. Almost the entire (99.6%) ground state RKR potential is constructed using the bound state experimental data which leads to a more accurate value of the dissociation energy (D″e=6024±6 cm−1). The feasibility of a continuously tunable near infrared Na2 laser based upon this radiative dissociation process is discussed. Finally, we present a comprehensive bibliography for the Na2 m...

The dissociation energy of the hydrogen molecule using long-range forces

Abstract New assignments of vibrational levels near dissociation in the B1Σ+u state of H2 indicate the virbrational quantum number is proportional to the one-sixth power of the binding energy, as expected theoretically from the long-range r−3 behavior of the internuclear potential. This is used to obtain an improved dissociation limit of 118377.7 ± 0.5 cm−1, corresponding to a ground state (X1Σ+g) dissociation energy D00 = 36118.6 ± 0.5 cm−1.

Laser cooling of molecules: A sequential scheme for rotation, translation, and vibration

A novel scheme is proposed for sequential cooling of rotation, translation, and vibration of molecules. More generally, this scheme manipulates and controls the states and energies of molecules. The scheme, while somewhat complex, is simpler and more feasible than simply providing a large number of synchronously but independently tunable lasers. The key component is a multiple single frequency laser (MSFL) in which a single narrow band pump laser generates an ensemble of resonant ‘‘stimulated Raman’’ (RSR) sidebands (subsequently amplified and selected) in a sample of the molecules to be cooled. Starting with a relatively cold molecular sample (e.g., a supersonic beam of Cs2), the rotation of molecules is cooled by sequential application of P branch electronic transition frequencies transverse to the molecular beam beginning at higher rotational angular momentum J. Then translation of molecules is cooled by application of multiple low J, P, and R branch transition frequencies which counterpropagate with t...

Spectroscopy and structure of the lithium hydride diatomic molecules and ions

All significant experimental measurements and many theoretical calculations of the spectroscopy and structure of the isotopic lithium hydrides ( 6LiH, 7LiH, 6LiD, 7LiD) are identified and reviewed. Published molecular constant determinations from conventional and laser spectroscopy are evaluated; recommended spectroscopic constants for the X  1Σ+, A  1Σ+, and B  1Π states are tabulated. Potential energy curves (RKR, IPA, and hybrid) for the X  1Σ+, A  1Σ+, and B  1Π states are evaluated and recommended curves are tabulated. Dissociation energy estimates are evaluated and recommended D0 and De values tabulated for X  1Σ+, A  1Σ+, and B 1Π states. Accurate electronic structure calculations (Hartree Fock or better) on this ‘‘workbench of theoretical chemistry’’ are listed and described briefly; all excited electronic states considered are included. Experimental and theoretical radiative and dipole properties are noted and discussed. Adiabatic corrections to the Born–Oppenheimer approximation are also reviewe...

Photoassociative Production and Trapping of Ultracold KRb Molecules

We have produced ultracold heteronuclear KRb molecules by the process of photoassociation in a two-species magneto-optical trap. Following decay of the photoassociated KRb*, the molecules are detected using two-photon ionization and time-of-flight mass spectroscopy of KRb+. A portion of the metastable triplet molecules thus formed are magnetically trapped. Photoassociative spectra down to 91 cm(-1) below the K(4s)+Rb(5p(1/2)) asymptote have been obtained. We have made assignments to all eight of the attractive Hunds case (c) KRb* potential curves in this spectral region.

The A 1Σ+–X 1Σ+ system of the isotopic lithium hydrides: The molecular constants, potential energy curves, and their adiabatic corrections

The molecular constants and their adiabatic corrections have been determined for the A 1Σ+–X 1Σ+ system of the isotopic lithium hydrides: 6LiH, 7LiH, 6LiD, and 7LiD. Using a fully quantum mechanical variational method, the potential energy curves (IPA potentials) are determined. Extending the variational method, we have obtained for the first time adiabatic corrections of potential energy curves from isotopic spectroscopic data. A significant difference between the potential energy curves of the lithium hydrides and the lithium deuterides has been observed. When 6Li was replaced by 7Li, a significant difference was only observed for the A 1Σ+ state, but not for the X 1Σ+ state.

Spectroscopy and Structure of the Alkali Hydride Diatomic Molecules and their Ions

All significant experimental measurements and theoretical calculations of the spectroscopy and structure of the alkali hydrides NaH, KH, RbH, and CsH, and the corresponding alkali deuterides, are identified and reviewed. Published molecular constant determinations from conventional and laser spectroscopy are evaluated; recommended spectroscopic constants for X 1Σ+ and A 1Σ+ states are tabulated. RKR and hybrid potential energy curves are evaluated; recommended RKR curves for X 1Σ+ and A 1Σ+ states are tabulated. Ground state dissociation energy (De) estimates are evaluated; recommended X 1Σ+ and A 1Σ+ state De and D0 values are tabulated. Accurate electronic structure calculations (Hartree–Fock or better) are listed and described briefly; all excited electron states considered are included. Experimental and theoretical radiative and dipole properties are noted and discussed. Calculations on the positive and negative ions of the four diatomic alkali hydrides are also listed and described briefly.

ULTRACOLD PHOTOASSOCIATIVE SPECTROSCOPY OF HETERONUCLEAR ALKALI-METAL DIATOMIC MOLECULES

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.