Three-body recombination in heteronuclear mixtures at finite temperature

Abstract

Within the universal zero-range theory, we compute the three-body recombination rate to deep molecular states for two identical bosons resonantly interacting with each other and with a third atom of another species, in the absence of weakly bound dimers. The results allow for a quantitative understanding of loss resonances at finite temperature and, combined with experimental data, can be used for testing the Efimov universality and extracting the corresponding three-body parameters in a given system. Curiously, we find that the loss rate can be dramatically enhanced by the resonant heavy-heavy interaction, even for large mass ratios where this interaction is practically irrelevant for the Efimov scaling factor. This effect is important for analysing the recent loss measurements in the Cs-Li mixture

Finite-temperature effects on a triatomic Efimov resonance in ultracold cesium

“…A further extension has been presented in Ref. [39] for mass-imbalanced three-body systems, which are in the focus of current experimental work 100 1000 10000 [ 18,19,40].…”

Efimov effect for heteronuclear three-body systems at positive scattering length and finite temperature

“…Including range corrections to the temperature-dependent three-body recombination process will enable us to understand Efimov physics even when a is not particularly large and might help us avoid the range of a values where higher partial-wave contributions are dominant. The effects of a finite intraspecies scattering length a 22 have been incorporated perturbatively [24] for |a 22 | |a| and T = 0 K and nonperturbatively [26] for |a 22 | ∼ |a| at finite T for a < 0;…”

“…(18) for each x to numerical values of phase shifts obtained from Eqs. (2) calculations for these systems [20,26,39,40] and are included in the S-wave three-body recombination rate for shallow and deep diatomic molecules.…”

“…Our results at lower temperatures indicate the minima at 5000a 0 can only be observed at temperatures well below 10 nK, which may not be experimentally feasible. give η * = 0.2 [26]. We adopt the use of η * = 0.2 and a * 0 = 610a 0 in Fig.…”

Unitary boson-boson and boson-fermion mixtures: third virial coefficient and three-body parameter on a narrow Feshbach resonance

“…In B − b bosonboson mixtures, this issue is worsened because two threebody parameters R t must be introduced, R BBb t and R bbB t , so that one cannot even fully absorb R t in a rescaling of the temperature as done in [18]. The second issue is experimental: when the Efimov effect is present in current experiments, strong three-body losses take place even in the zero-range limit k F b → 0, where k F is a Fermi wavenumber and b the interaction range, due to recombination into strongly bound dimers [35,36]. This is due to the fact that the probability that three atoms are within a radius b vanishes too slowly, only as b 2 , whereas the recombination rate in such a close-atom configuration is ∝ 2 /m r b 2 [37].…”