Erratum: Laser-intensity dependence of photoassociation in ultracold metastable helium [Phys. Rev. A<b>80</b>, 023417 (2009)]

The effects of non-adiabatic and Coriolis couplings on the bound states of the He(2 3 S 1 )+He(2 3 P j ) system, where j = 0, 1, 2, are investigated using the recently available ab initio short-range 1,3,5 Σ + g,u and 1,3,5 Π g,u potentials computed by Deguilhem et al. (J. Phys. B: At. Mol. Opt. Phys. 42 (2009) 015102). Three sets of calculations have been undertaken: single-channel, multichannel without Coriolis couplings and full multichannel with Coriolis couplings. We find that nonadiabatic effects are negligible for 0 − u , 0 ± g , 1 u , 2 g , 2 u , 3 g Hund case (c) sets of levels in the j = 2 asymptote but can be up to 15% for some of the 0 + u and 1 g sets of levels where near degeneracies are present in the single-channel diagonalized potentials. Coriolis couplings are most significant for weakly bound levels, ranging from 1-5% for total angular momenta J = 1, 2 and up to 10% for J = 3. Levels near the j = 1 and j = 0 asymptotes agree closely with previous multichannel calculations based upon long-range potentials constructed from retarded resonance dipole and dispersion interactions. Assignment of theoretical levels to experimental observations using criteria based upon the short-range character of each level and their coupling to metastable ground states produces well matched assignments for the majority of observations. After a 1% increase in the slope of the 5 Σ + g,u and 5 Π g,u input potentials near the classical turning point is applied, improved matching of previous assignments is obtained and further assignments can be made, reproducing very closely the number of experimental observations.

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“…The LS coupling scheme diagonalizesĤ el whereas the jj coupling scheme diagonalizesĤ fs . We choose to use the body-fixed jj coupled states [9]…”

Section: Coupled-channel Approachmentioning

confidence: 99%

Effects of non-adiabatic and Coriolis couplings on the bound states of He(2³S)+He(2³P)

Cocks¹,

Whittingham²,

Peach³

2010

J. Phys. B: At. Mol. Opt. Phys.

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“…This means that the dressed state formalism or the R-dependent coupling method need not be employed to solve the equations. However, for consistency between the two calculations, the R-dependent tail-off is introduced exactly as it was used in [3].…”

Section: Resultsmentioning

confidence: 99%

“…Of particular interest is PA in metastable helium where release of the large internal energy during collisions provides unique experimental investigation strategies. We have recently analysed the PA process [3] and obtained detailed information of the laser intensity dependence of the line shifts and widths of the resonance peaks in the PA spectra of ultracold metastable helium excited to the J = 1, 0 + u rovibrational states in the 2 3 S 1 + 2 3 P 0 asymptote. Two variants of a full nonperturbative multichannel, closecoupled treatment were used to obtain the required scattering matrix S in the presence of the non-vanishing asymptotic radiative coupling, one based upon dressed states, and the other on a modified radiative coupling that vanishes asymptotically.…”

Section: Introductionmentioning

confidence: 99%

“…The validity of the dipole approximation at large interatomic separations of O(10 5 ) a 0 is questionable, at least when weakly bound levels are considered. In this paper we study the effects of the non-dipole contributions to the PA spectra in metastable helium by firstly deriving an expression for the matrix elements of the laser coupling which fully includes the exp(ik • r i ) factors and then re-do the multichannel calculations of [3] using these matrix elements.…”

Section: Introductionmentioning

confidence: 99%

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Photoassociation spectra and the validity of the dipole approximation for weakly bound dimers

Cocks

Whittingham

2010

Phys. Rev. A

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Photoassociation (PA) of ultracold metastable helium to the 2s2p manifold is theoretically investigated using a non-perturbative close-coupled treatment in which the laser coupling is evaluated without assuming the dipole approximation. The results are compared with our previous study [Cocks and Whittingham, Phys. Rev. A 80, 023417 (2009)] that makes use of the dipole approximation. The approximation is found to strongly affect the PA spectra because the photoassociated levels are weakly bound, and a similar impact is predicted to occur in other systems of a weakly bound nature. The inclusion or not of the approximation does not affect the resonance positions or widths, however significant differences are observed in the background of the spectra and the maximum laser intensity at which resonances are discernable. Couplings not satisfying the dipole selection rule |J − 1| ≤ J ′ ≤ |J + 1| do not lead to observable resonances.

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“…Unfortunately there is not a clear and obvious choice for the preparation of a heteronuclear experimental gas mixture, so we have not included a set of observability criteria in this paper. It would be desirable, in such a case, to perform a scattering calculation similar to [15], which would consider the appropriate incoming 2s + 2s channels and laser coupling terms. The full scattering matrix could then be obtained, along with various cross sections relevant to experiment.…”

Section: Discussionmentioning

confidence: 99%

Long-range states in excited ultracold³He–⁴He dimers

Cocks

Peach

Whittingham

2015

J. Phys. B: At. Mol. Opt. Phys.

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Abstract. Long-range bound states of the excited heteronuclear 3 He * -4 He * system that dissociate to either 3 He(1s2s 3 S 1 ) + 4 He(1s2p 3 P j ) or 3 He(1s2p 3 P j ) + 4 He(1s2s 3 S 1 ), where j = 0, 1, 2, are investigated using both single-channel and multichannel calculations in order to analyse the effects of Coriolis and non-adiabatic couplings. The multichannel calculations predict two groups of resonances above the lowest asymptotic energy. One of these groups dissociates to an atomic pair with the 2p excitation on the fermionic atom and the other dissociates to two asymptotes which correspond to the 2p excitation on either atom. Many of these resonances could be identified with levels in the single-channel calculation although the differences in energies were large. The total parity was found to have a significant influence on the ability to make these identifications. No purely bound states were found, although several resonances with line widths smaller than 1 MHz were obtained.

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Erratum: Laser-intensity dependence of photoassociation in ultracold metastable helium [Phys. Rev. A80, 023417 (2009)]

Abstract: Erratum: Laser-intensity dependence of photoassociation in ultracold metastable helium [Phys. Rev. A 80, 023417 (2009)]

Cited by 3 publications

References 1 publication

Effects of non-adiabatic and Coriolis couplings on the bound states of He(2³S)+He(2³P)

Effects of non-adiabatic and Coriolis couplings on the bound states of He(2³S)+He(2³P)

Photoassociation spectra and the validity of the dipole approximation for weakly bound dimers

Long-range states in excited ultracold³He–⁴He dimers

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Erratum: Laser-intensity dependence of photoassociation in ultracold metastable helium [Phys. Rev. A80, 023417 (2009)]

Abstract: Erratum: Laser-intensity dependence of photoassociation in ultracold metastable helium [Phys. Rev. A 80, 023417 (2009)]

Cited by 3 publications

References 1 publication

Effects of non-adiabatic and Coriolis couplings on the bound states of He(23S)+He(23P)

Effects of non-adiabatic and Coriolis couplings on the bound states of He(23S)+He(23P)

Photoassociation spectra and the validity of the dipole approximation for weakly bound dimers

Long-range states in excited ultracold3He*–4He* dimers

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Effects of non-adiabatic and Coriolis couplings on the bound states of He(2³S)+He(2³P)

Effects of non-adiabatic and Coriolis couplings on the bound states of He(2³S)+He(2³P)

Long-range states in excited ultracold³He–⁴He dimers