Resonantly Interacting Fermi-Fermi Mixture of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi>Dy</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>161</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">K</mml:mi></mml:mrow><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>40</mml:mn></mml:mrow></mml:mmultiscripts></mml:mrow></mml:math>
Cornelis Ravensbergen, Elisa Soave, Vincent Le Corre, Marian Kreyer, Bo Huang, Emil Kirilov, Rudolf Grimm
Abstract
We report on the realization of a Fermi-Fermi mixture of ultracold atoms that combines mass imbalance, tunability, and collisional stability. In an optically trapped sample of ^{161}Dy and ^{40}K, we identify a broad Feshbach resonance centered at a magnetic field of 217 G. Hydrodynamic expansion profiles in the resonant interaction regime reveal a bimodal behavior resulting from mass imbalance. Lifetime studies on resonance show a suppression of inelastic few-body processes by orders of magnitude, which we interpret as a consequence of the fermionic nature of our system. The resonant mixture opens up intriguing perspectives for studies on novel states of strongly correlated fermions with mass imbalance.