Long-lived complexes and signatures of chaos in ultracold 
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi mathvariant="normal">K</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>
+Rb collisions

Croft, James; Balakrishnan, N.; Kendrick, Brian K.

doi:10.1103/physreva.96.062707

Cited by 32 publications

(32 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For ultracold collisions of Dy and Er atoms it was measured [16,25] and theoretically confirmed [16,44,[64][65][66][67] that the interplay of anisotropic electronic and dipolar interactions leads to the chaotic spectra of Feshbach resonances being the signature of the level repulsion following the predictions of the Gaussian Orthogonal Ensemble of random matrices [68]. Similar results were predicted for atom-molecule collisions [69][70][71]. To verify the above hypothesis in the considered case, in Fig.…”

Section: Numerical Results and Discussionsupporting

confidence: 75%

Magnetically tunable Feshbach resonances in ultracold gases of europium atoms and mixtures of europium and alkali-metal atoms

2018

View full text Add to dashboard Cite

We investigate magnetically tunable Feshbach resonances between ultracold europium atoms and between europium and alkali-metal atoms using multichannel quantum scattering calculations. For ultracold gases of europium atoms both homonuclear 153 Eu+ 153 Eu and heteronuclear 151 Eu+ 153 Eu systems are studied. Calculations for mixtures of europium and alkali-metal atoms are carried out for prototype systems of 153 Eu+ 87 Rb and 153 Eu+ 7 Li. We analyze the prospects for the control of scattering properties, observation of quantum chaotic behavior, and magnetoassociation into ultracold polar and paramagnetic molecules. We show that favorable resonances can be expected at experimentally feasible magnetic-field strengths below 1000 G for all investigated atomic combinations. For Eu atoms, a rich spectrum of resonances is expected as a result of the competition between relatively weak short-range spin-exchange and strong long-range magnetic dipole-dipole interactions, where the dipolar interaction induces measurable resonances. A high density of resonances is expected at magnetic-field strengths below 200 G without pronounced quantum chaos signatures. The present results may be useful for the realization and application of dipolar atomic and molecular quantum gases based on europium atoms in many-body physics.

show abstract

Section: Numerical Results and Discussionsupporting

confidence: 75%

Magnetically tunable Feshbach resonances in ultracold gases of europium atoms and mixtures of europium and alkali-metal atoms

2018

View full text Add to dashboard Cite

show abstract

“…Just as in Ref. [20] we only take into account even j to account for the indistinguishability of the K-atoms. If j is even and J = 0, then l = n and p = 1, therefore g N Jp = δ p,1 .…”

Section: A K 2 -Rbmentioning

confidence: 99%

Quasiclassical method for calculating the density of states of ultracold collision complexes

Christianen¹,

Karman

Groenenboom³

2019

Phys. Rev. A

132

View full text Add to dashboard Cite

We derive a quasiclassical expression for the density of states (DOS) of an arbitrary, ultracold, N -atom collision complex, for a general potential energy surface (PES). We establish the accuracy of our quasiclassical method by comparing to exact quantum results for the K 2 -Rb and NaK-NaK systems, with isotropic model PESs. Next, we calculate the DOS for an accurate NaK-NaK PES to be 0.124 µK −1 , with an associated Rice-Ramsperger-Kassel-Marcus (RRKM) sticking time of 6.0 µs. We extrapolate the DOS and sticking times to all other polar bialkali-bialkali collision complexes by scaling with atomic masses, equilibrium bond lengths, dissociation energies, and dispersion coefficients. The sticking times calculated here are two to three orders of magnitude shorter than those reported by Mayle et al. [Phys. Rev. A 85, 062712 (2012)]. We estimate dispersion coefficients and collision rates between molecules and complexes. We find that the sticking-amplified three-body loss mechanism is not likely the cause of the losses observed in the experiments. * gerritg@theochem.ru.nl arXiv:1905.06691v2 [cond-mat.quant-gas]

show abstract

“…For collisions of RbCs in the rovibrational ground state, they predict a density of states of ρ/k B = 942 µK −1 and a lifetime of 45 ms for the RbCs+RbCs complex (hereafter, (RbCs) 2 ) [48]. However, recent work indicates that the density of states was over-estimated by Mayle et al, leading to complex lifetimes that are 2 to 3 orders of magnitude too large [49,50]. Specifically, Christianen et al have estimated the rate of (NaK) 2 +NaK complex-molecule collisions [51], and find that for typical experimental densities, the lifetime associated with this rate is significantly longer than τ c .…”

mentioning

confidence: 99%

Loss of Ultracold Rb87Cs133 Molecules via Optical Excitation of Long-Lived Two-Body Collision Complexes

et al. 2020

View full text Add to dashboard Cite

We show that the lifetime of ultracold ground-state 87 Rb 133 Cs molecules in an optical trap is limited by fast optical excitation of long-lived two-body collision complexes. We partially suppress this loss mechanism by applying square-wave modulation to the trap intensity, such that the molecules spend 75% of each modulation cycle in the dark. By varying the modulation frequency, we show that the lifetime of the collision complex is 0.53 ± 0.06 ms in the dark. We find that the rate of optical excitation of the collision complex is 3 +4 −2 × 10 3 W −1 cm 2 s −1 for λ = 1550 nm, leading to a lifetime of < 100 ns for typical trap intensities. These results explain the two-body loss observed in experiments on nonreactive bialkali molecules.

show abstract

Long-lived complexes and signatures of chaos in ultracold K2 +Rb collisions

Cited by 32 publications

References 71 publications

Magnetically tunable Feshbach resonances in ultracold gases of europium atoms and mixtures of europium and alkali-metal atoms

Magnetically tunable Feshbach resonances in ultracold gases of europium atoms and mixtures of europium and alkali-metal atoms

Quasiclassical method for calculating the density of states of ultracold collision complexes

Loss of Ultracold Rb87Cs133 Molecules via Optical Excitation of Long-Lived Two-Body Collision Complexes

Contact Info

Product

Resources

About