Rabi Oscillation Spectroscopy of Multibranch Fermi Polarons

Our study investigates Fermi polarons realized by highly spin-imbalanced Fermi gas of 6 Li atoms confined in an optical box. Utilizing a tunable radio-frequency field, we observe a distinctive steady state on the Bose-Einstein condensate side of the Feshbach resonance (1/k_Fa>0), revealing the coexistence of attractive and repulsive polarons. The dynamical response towards the steady state exhibits a two-mode damped Rabi oscillation, highlighting the system's complex nature as a multi-branch quantum many-body system.