Dipole-Dipole Resonance Forces

King, G.W.; Vleck, J. H. Van

doi:10.1103/physrev.55.1165

Cited by 175 publications

(39 citation statements)

References 13 publications

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“…Studies of these long-range interactions in homonuclear diatomic molecules have continued to the present day. [2][3][4][5][6][7][8][9][10] Recently, the rapid development in laser cooling, trapping and Bose-Einstein condensation has again triggered many new investigations of the long-range interactions of the alkali dimers. [9][10][11][12][13][14][15][16] This is because accurate knowledge of the long-range potential curves ͑especially correlated with the ground and the first-excited asymptotes such as 4sϩ4s and 4sϩ4p for K 2 ͒ is crucial in the interpretation of many new physical phenomena associated with ultracold atoms, such as cold collision dynamics, 17,18 photoassociative ionization, [19][20][21] fine-and hyperfine predissociation, [22][23][24] optical suppression of inelastic collisions, [25][26][27] as well as the stability of Bose-Einstein condensates.…”

Section: Introductionmentioning

confidence: 99%

Long-range interaction of the 39K(4s)+39K(4p) asymptote by photoassociative spectroscopy. I. The g− pure long-range state and the long-range potential constants

Wang

Gould

Stwalley

1997

The Journal of Chemical Physics

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Long-range interaction of the 39K(4s)+39K(4p) asymptote by photoassociative spectroscopy. I. The 0g− pure long-range state and the long-range potential constants This paper reports on a comprehensive study of the long-range interaction of the 39 K(4s) ϩ 39 K(4p) asymptotic system. We present a detailed discussion of the R-dependent angular momentum couplings and correlation between the Hund's case ͑a͒ and case ͑c͒ molecular states. Analytical expressions for the 16 adiabatic Hund's case ͑c͒ long-range potential curves are derived including the higher order dispersion forces and the effects of retardation. Experimentally, six Hund's case ͑c͒ long-range molecular states ͑0 u ϩ , 1 g , and 0 g Ϫ dissociating to the 4 2 S 1/2 ϩ4 2 P 3/2 asymptote and 0 u ϩ , 1 g , and 0 g Ϫ to the 4 2 S 1/2 ϩ4 2 P 1/2 limit͒ are observed with rovibrational resolution by photoassociative spectroscopy of ultracold 39 K atoms in a high density magneto-optical trap ͑MOT͒. Among the six observed long-range states, the upper 0 g Ϫ ''pure long-range'' state has negligible short-range chemical exchange contributions and the measured molecular binding energies (vϭ0 -26) are used to precisely determine the long-range potential constants of the 4sϩ4 p interaction. We determine: C 3 ⌸ ϭ8.436(14) a.u., C 3 ⌺ ϭ16.872(28) a.u., C 6 ⌸ ϭ6272(94) a.u., and C 6 ⌺ ϭ9365(141) a.u.. Molecular constants for the three special pure long-range states, the 0 g Ϫ and 1 u ͑dissociating to the 4 2 P 3/2 limit and with potential minimum͒ and the 1 u ͑dissociating to the 4 2 P 1/2 and with potential maximum͒, are reported. The internal consistency of the theoretical model used in this work is confirmed by the excellent agreement between the long-range potential curve of the 1 g state obtained in present work ͑from the 0 g Ϫ state͒ and the long-range portion of the RKR potential curve of the 1 1 ⌸ g state previously determined by conventional molecular spectroscopy. The radiative lifetime of the K 4 p state derived from the dipole-dipole interaction constant C 3 ⌸ is also in excellent agreement with a recent fast-beam measurement.

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Section: Introductionmentioning

confidence: 99%

Long-range interaction of the 39K(4s)+39K(4p) asymptote by photoassociative spectroscopy. I. The g− pure long-range state and the long-range potential constants

Wang

Gould

Stwalley

1997

The Journal of Chemical Physics

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“…We use this technique to study the long-range interatomic potential of the first excited state of Li2. This resonant dipole-dipole interaction depends on the 2P atomic lithium radiative lifetime [4]. Methods to extract long-range potential coefficients, assuming the asymptotic long-range form of the potential, have been developed previously [5] and have been applied to ultracold photoassociation spectra [2,3].…”

mentioning

confidence: 99%

Precise atomic radiative lifetime via photoassociative spectroscopy of ultracold lithium

et al. 1995

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We have obtained spectra of the high-lying vibrational levels of the 1 X state of Liz [5] and have been applied to ultracold photoassociation spectra [2,3]. However, in those investigations the details of the potential are not accounted for, and the accuracy of the resulting long-range coefficients is only a few percent. We are able to extract a more precise value for the long-range potential coefficient, and therefore, the atomic radiative lifetime by fitting a model of the full interaction potential to the observed photoassociation spectrum. [7].Unfortunately, the theoretical value differs from the experimental one by more than 0.7%, or more than four standard deviations. Clearly, the resolution of this discrepancy is a high priority.The experiment uses a six-beam magneto-optical trap (MOT) [8] to produce an ultracold lithium vapor [9]. A 500-mW probe laser beam with a Gaussian beam waist (1/e radius) of 500 p, m is directed through and retroreflected back through the trapped atom cloud to induce photoassociation. As the probe is tuned to the red of the 2S»2-2P»2 atomic transition, it can excite colliding groundstate atoms into various high-lying vibrational levels of the molecular excited-state manifold. These newly formed diatomic molecules decay into a bound ground state of the molecule or into a dissociative continuum of two groundstate atoms that may gain enough kinetic energy to escape the trap. These combined processes result in an observable reduction in trap-laser-induced fluorescence, which is monitored by a photodiode. Vibrational levels up to 3 THz (100 cm ) red of the 2S»2-2Pi/2 atomic transition have been observed in this manner (Fig. 1) [10].

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“…The atoms, respectively, in the 1s and 2p states, have no permanent dipole moment when isolated, but in the case of interacting identical atoms no distinction can be made as to which atom is excited and which one is in the ground state, giving rise to a superposition as is expressed in (4). The resulting atomic dipole moments, having a fixed relative orientation, give rise to the resonant dipole-dipole interaction [23]. In the case of HD however, no such superposition can exist and no resonant dipole moments can be formed, i.e., the R −3 -term must vanish.…”

Section: Resultsmentioning

confidence: 99%

Gerade/ungerade symmetry-breaking in HD at the n = 2 dissociation limit

Lange¹,

Reinhold²,

Hogervorst³

et al. 2000

Can. J. Phys.

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Abstract:We report on a study of the I 1 g outer well state of HD. Via a resonance-enhanced XUV + IR (extreme ultraviolet + infrared) excitation scheme, rovibronic levels (v = 0-2, J = 1-4) are populated and probed by pulsed lasers. Level energies are measured with an accuracy of ≈0.03 cm −1 . Due to gerade-ungerade symmetry breaking, the long-range behavior of the I potential in HD deviates from that of H 2 and D 2 . When this deviation is taken into account a semi-empirical potential for the I [Traduit par la rédaction]

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Dipole-Dipole Resonance Forces

Cited by 175 publications

References 13 publications

Long-range interaction of the 39K(4s)+39K(4p) asymptote by photoassociative spectroscopy. I. The g− pure long-range state and the long-range potential constants

Long-range interaction of the 39K(4s)+39K(4p) asymptote by photoassociative spectroscopy. I. The g− pure long-range state and the long-range potential constants

Precise atomic radiative lifetime via photoassociative spectroscopy of ultracold lithium

Gerade/ungerade symmetry-breaking in HD at the <i><b>n</b></i> = <b>2</b> dissociation limit

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