title: Realization of a strongly interacting Bose-Fermi mixture from a two-component Fermi gas.
abstract: We show the emergence of a strongly interacting Bose-Fermi mixture from a two-component Fermi mixture with population imbalance. By analyzing in situ density profiles of 6Li atoms in the BCS-BEC crossover regime, we identify a critical interaction strength, beyond which all minority atoms pair up with majority atoms and form a Bose condensate. This is the regime where the system can be effectively described as a boson-fermion mixture. We determine the dimer-fermion and dimer-dimer scattering lengths and beyond-mean-field contributions. Our study realizes a gedanken experiment of bosons immersed in a Fermi sea of one of their constituents, revealing the composite nature of the bosons.
authors.affiliation: Department of Physics, MIT-Harvard Center for Ultracold Atoms, and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. yishin@mit.edu
authors.forename: Yong-il
authors.initials: YI
authors.lastname: Shin
authors.forename: André
authors.initials: A
authors.lastname: Schirotzek
authors.forename: Christian H
authors.initials: CH
authors.lastname: Schunck
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ketterle