In this article, the authors presented measurements of interspecies thermalization between ultracold samples of 133Cs and either 174Yb or 170Yb, where the two species were trapped in a far-off-resonance optical dipole trap and 133Cs was sympathetically cooled by Yb.
Abstract:
We present measurements of interspecies thermalization between ultracold samples of 133Cs and either 174Yb or 170Yb. The two species are trapped in a far-off-resonance optical dipole trap and 133Cs is sympathetically cooled
by Yb. We extract effective interspecies thermalization cross sections by fitting the thermalization measurements
to a kinetic model, giving σCs174Yb = (5 ± 2) × 10−13 cm2 and σCs170Yb = (18 ± 8) × 10−13 cm2. We perform
quantum scattering calculations of the thermalization cross sections and optimize the CsYb interaction potential
to reproduce the measurements. We predict scattering lengths for all isotopic combinations of Cs and Yb. We
also demonstrate the independent production of 174Yb and 133Cs Bose-Einstein condensates using the same
optical dipole trap, an important step toward the realization of a quantum-degenerate mixture of the two
species.
TL;DR: In this article, the first observation of magnetic Feshbach resonances in a system containing a closed-shell atom, Sr, interacting with an alkali atom, Rb, was made.
TL;DR: In this article, magnetically tunable Feshbach resonances in ultracold collisions between ground-state Yb and Cs atoms were investigated using coupled-channel calculations based on an interaction potential recently determined from photoassociation spectroscopy.
TL;DR: In this paper, a variety of calculations on cold and ultracold scattering, with a broad theme of how best to consider and understand complex systems in simple ways, are presented.
TL;DR: In this article, the collective dynamics of a quantum degenerate Bose-Bose mixture of Cs and Yb with attractive interspecies interactions were investigated, and a broad Feshbach resonance was used to explore the stability of the degenerate mixture, and observed collapse of the Cs condensate mediated by the attractive Cs-Yb interaction.
TL;DR: In this paper, a dual-species evaporation is performed in a microscopic optical dipole trap that combines light at 1070 nm and 532 nm to enable control of the trap depths for Cs and Yb.
Q1. What have the authors contributed in "Interspecies thermalization in an ultracold mixture of cs and yb in an optical trap" ?
In this paper, the authors measured thermalization in an ultracold mixture of Cs and Yb and used a kinetic model to determine the cross sections for interspecies thermalization, taking account of additional heating effects that prevent complete thermalization of the two species.
Q2. How do the authors evaluate the (1) from S-matrix elements?
The authors perform scattering calculations using the MOLSCAT package [72], with the SBE post-processor [73] to evaluate σ (1)η from S-matrix elements.
Q3. What is the polarizability of Cs at 532 nm?
The negative polarizability of Cs at 532 nm [αCs(532 nm) = −210 a30] balances the large positive polarizability at 1070 nm [αCs(1070 nm) = 1140 a30].
Q4. What is the probability of Cs+Yb scattering lengths?
The interspecies Cs+Yb scattering lengths are predicted to have moderate magnitudes (<200 a0) for all Yb isotopes except 176Yb, with good prospects of creating doubly degenerate mixtures.
Q5. Why is the value for recombination heating reasonable?
The value for recombination heating is reasonable because the Cs trap depth of 85 μK is large enough to trap some of the products of the three-body recombination event.
Q6. Why does Eq. (7) contain an extra factor of x?
Note that Eq. (7) contains an extra factor of x because higher-energy collisions transfer more energy for the same deflection angle.
Q7. Why is the Yb number decay so short?
The timescale of this decay is much shorter than the single-species 1/e background lifetime of 15 s and the authors attribute the number loss to sympathetic evaporation [2].
Q8. What is the reason for the poor efficiency of the transfer into the ODT?
The heating and poor efficiency of the transfer into the ODT are due to the poor mode matching of the DRSC-cooled cloud and the deep ODT (UCs = 85 μK).
Q9. What is the interspecies scattering length for 174Yb?
Fig. 5 shows that the interspecies scattering length is predicted to be of moderate magnitude (<200 a0) for all Yb isotopes except 176Yb.