Collisions of ultracold molecules in bright and dark optical dipole traps

Bause, Roman; Schindewolf, Andreas; Tao, Renhao; Duda, Marcel; Chen, Xingyan; Quéméner, Goulven; Karman, Tijs; Christianen, Arthur; Bloch, Immanuel; Luo, Xinyu

doi:10.1103/physrevresearch.3.033013

Cited by 65 publications

(39 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For some gases these collisions lead to reactions [1,2,13,14], but in others long-lived collision complexes are formed [12,[15][16][17]. In current experiments most of these collision complexes are lost from the gas, but it may be possible to recover these complexes by eliminating short-range loss in repulsive box potentials [17,18], although there might be additional loss mechanisms that need to be eliminated [19,20].…”

Section: Introductionmentioning

confidence: 86%

Ab initio study of the reactivity of ultracold RbSr + RbSr collisions

2022

Self Cite

View full text Add to dashboard Cite

In this article we perform ab initio calculations in order to assess the reactivity of ultracold RbSr (2Σ+) + RbSr (2Σ+) collisions occurring on the singlet as well as the triplet potential. At ultracold energies reactions are energetically possible if they release energy, i.e., they are exoergic. The exoergicity of reactions between RbSr molecules producing diatomic molecules are known experimentally. We extend this to reactions producing triatomic molecules by calculating the binding energy of the triatomic reaction products. We find that, in addition to the formation of Rb2 and Rb2+Sr2 in singlet collisions, also the formation of Sr2Rb and Rb2Sr molecules in both singlet and triplet collisions is exoergic. Hence, the formation of these reaction products is energetically possible in ultracold collisions. For all exoergic reactions the exoergicity is larger than 1000 cm-1. We also find barrierless qualitative reaction paths leading to the formation of the Rb2Sr, Sr2Rb, and singlet Rb2 reaction products. These reaction paths imply the existence of a qualitative reaction path with a submerged barrier for the creation of the singlet Rb2+Sr2 reaction product. Because of the existence of these reactions we expect ultracold RbSr collisions to result in almost universal loss even on the triplet potential. Our results can be contrasted with collisions between alkali diatoms, where the formation of triatomic reaction products is endoergic, and with collisions between ultracold SrF molecules, where during triplet collisions only the spin-forbidden formation of singlet SrF2 is allowed.

show abstract

Section: Introductionmentioning

confidence: 86%

Ab initio study of the reactivity of ultracold RbSr + RbSr collisions

2022

Self Cite

View full text Add to dashboard Cite

show abstract

“…This can be seen later in the second line of Eq. (11). For the direct process, the induced dipole moments involved are d 0→0 (black curve) and d 2→2 (blue curve), which are positive and negative around E * , respectively.…”

Section: B Second Simplification: Removal Of the Rotational Structurementioning

confidence: 99%

“…The loss processes dominate over the elastic ones at the typical temperatures of hundreds of nanokelvins reached in the experiments, leading to unfavorable conditions for long-lived gases, efficient evaporative cooling and quantum degeneracy. The overall losses, often referred to as quenching processes, include either reactive processes when chemical reactions are possible [1,2] or complex formation processes [3][4][5][6][7][8][9][10][11]. If the molecules are initially prepared in excited rovibrational states, inelastic processes can also occur and contribute to the quenching.…”

Section: Introductionmentioning

confidence: 99%

Model for two-body collisions between ultracold dipolar molecules around a Förster resonance in an electric field

Lassablière,

Quéméner

2022

Preprint

Self Cite

View full text Add to dashboard Cite

We propose a one-channel, simple model to describe the dynamics of ultracold dipolar molecules around a Förster resonance. Slightly above a specific electric field, a collisional shielding can take place, suppressing the molecular losses in a gas. The overall description of the quantum physical mechanism comes back to the dynamics on a unique energy surface, which depends on the relative distance and angular approach of the molecules. This surface enables to interpret how the dipole moments of the molecules are induced and interlocked by the electric field and the dipole-dipole interaction during the process, especially when the shielding is triggered. Averaging the relative angular motion over a unique partial wave (the lowest one when the ultracold regime is reached), the model reproduces well the behaviour of the rate coefficients observed experimentally and predicted theoretically [Matsuda et al., Science 370, 1324(2020 Li et al., Nat. Phys. 17, 1144]. This economic model encapsulates the main physics of the quantum process. Therefore, it can be used as an alternative to a full quantum dynamical treatment and is promising for future studies of collisions involving more bodies.

show abstract

“…Studies with dipolar ground state molecules are enabling advances in quantum chemistry [5][6][7][8] and have exciting prospects for quantum simulation [9,10], quantum computing [11][12][13] and the investigation of novel quantum phases [14,15]. Their electric dipole moment gives rise to tunable long-range interactions that can be controlled via external electric [7,16,17] or microwave [18][19][20] fields. Many applications of dipolar molecules will require quantum degenerate molecular gases.…”

mentioning

confidence: 99%

“…This will be of critical interest given the plethora of open questions regarding the formation of collision complexes and loss processes in ultracold molecular gases [60,61]. While recent experiments with RbCs [62] and KRb [63] have shown evidence for the formation of collision complexes that undergo loss after photoexcitation (e.g., via trap light), experiments with NaK [17] and NaRb [64] have not provided direct evidence for complex formation dynamics. NaCs will provide a valuable data point in this fast evolving field.…”

mentioning

confidence: 99%

Ultracold Gas of Dipolar NaCs Ground State Molecules

Stevenson¹,

Lam²,

Bigagli³

et al. 2022

Preprint

View full text Add to dashboard Cite

We report on the creation of bosonic NaCs molecules in their absolute rovibrational ground state via stimulated Raman adiabatic passage. We create ultracold gases with up to 22,000 dipolar NaCs molecules at a temperature of 300(50) nK and a peak density of 1.0(4) × 10 12 cm −3 . We demonstrate comprehensive quantum state control by preparing the molecules in a specific electronic, vibrational, rotational, and hyperfine state. Employing the tunability and strength of the permanent electric dipole moment of NaCs, we induce dipole moments of up to 2.6 D. Dipolar systems of NaCs molecules are uniquely suited to explore strongly interacting phases in dipolar quantum matter.techniques to be highly effective as they generally scale proportional to higher powers of d [41][42][43]. For resonant collisional shielding in NaCs, a superb ratio of elastic to inelastic collisions of 10 6 has been predicted [37,42]; for microwave shielding, the large dipole moment will facilitate the required strong microwave coupling between the ground and first ex-

show abstract

Collisions of ultracold molecules in bright and dark optical dipole traps

Cited by 65 publications

References 64 publications

Ab initio study of the reactivity of ultracold RbSr + RbSr collisions

Ab initio study of the reactivity of ultracold RbSr + RbSr collisions

Model for two-body collisions between ultracold dipolar molecules around a Förster resonance in an electric field

Ultracold Gas of Dipolar NaCs Ground State Molecules

Contact Info

Product

Resources

About