Bose polarons in a homogeneous 3D Bose-Einstein condensate

We study Bose polarons in a homogeneous Bose-Einstein condensate, from weak to strong impurity-boson interactions. Our uniform ³⁹K condensate is produced in an optical-box trap, the polarons are formed using rf-injection between spin states, and the impurity-boson interactions are tuned via an interstate magnetic Feshbach resonance. We measure the polaron energy and spectral response across the resonance, observing reduced inhomogeneous broadening compared to previous harmonic-trap experiments. We also explore the effects of condensate density and impurity concentration.