Collisional Stability ofK40Immersed in a Strongly Interacting Fermi Gas ofLi6

Abstract

We investigate the collisional stability of a sample of 40K atoms immersed in a tunable spin mixture of 6Li atoms. In this three-component Fermi-Fermi mixture, we find very low loss rates in a wide range of interactions as long as molecule formation of 6Li is avoided. The stable fermionic mixture with two resonantly interacting spin states of one species together with another species is a promising system for a broad variety of phenomena in few- and many-body quantum physics.

Thermodynamics of Ultracold Fermi Gases

“…Applying our method requires to independently measure the gas temperature, which is notoriously di cult in the case of strong interactions. Inspired by the Innsbruck group [73], we implemented a new thermometry for strongly-interacting gases: the temperature is measured on a small amount of weakly-interacting 7 Li atoms, immersed in the 6 Li cloud and at thermal equilibrium with it.…”

“…The temperature cannot be extracted from the cloud image without invoking a model, since the relation between density pro le and temperature is precisely given by the equation of state we want to measure. Inspired by the Innsbruck group [73], we developed a new thermometry method, using 7 Li atoms immersed in the 6 Li gas, and at thermal equilibrium with it. The temperature is measured on the 7 Li component through its size after time-of-ight, a technique speci c to weakly-interacting gases.…”

“…This indicates a good thermalization e ciency even at the lowest temperatures. This has to be compared with the experimental results from [73] obtained on a mixture of 6 Li and 40 K. A steady state is reached after more than 3 s, and the nal temperatures for the 6 Li cloud and the 40 K cloud di er by 30%, probably due to di erent heating rates for the two species. In our case, 6 Li and 7 Li atoms experiencing exactly the same trapping potential, we expect trap-induced heating to be almost identical for the two species and therefore the nal 6 Li and 7 Li temperatures to be identical.…”

Dimer-atom scattering between two identical fermions and a third particle

“…Our results are relevant to the quantum phases of two-species Fermi-Fermi [10][11][12][13][14][15]. and Bose-Fermi [16][17][18][19] mixtures of atomic gases in the molecular limit.…”

Interspecies thermalization in an ultracold mixture of Cs and Yb in an optical trap

“…We predict scattering lengths for all isotopic combinations of Cs and Yb. We also demonstrate the independent production of 174 Yb and 133 Cs Bose-Einstein condensates using the same optical dipole trap, an important step towards the realization of a quantum-degenerate mixture of the two species.The realization of ultracold atomic mixtures [1][2][3][4][5][6][7][8][9][10][11][12] has opened up the possibility of exploring new regimes of few-and many-body physics. Such mixtures have been used to study Efimov physics [13][14][15], probe impurities in Bose gases [16], and entropically cool gases confined in an optical lattice [17].…”